Can low melatonin levels and/or LED lights cause or exacerbate macular degeneration?

I have two questions that may or may not be interconnected. My first question is:

Does melatonin prevent macular degeneration? Could low melatonin levels (caused by blue-rich light exposure in the evening and night and/or by insuffient sleep) heighten the risk for macular degeneration due to shorter amount of time that melatonin scavenges free radicals in the retina?

  • Evidence is conflicting as to whether exposure to sunlight contributes to the development of macular degeneration. A recent study on 446 subjects found it does not [1]. Other research, however, has shown high-energy visible light ("blue wavelengths") may contribute to age-related macular degeneration [2 and 3].

  • Data indicates that melatonin, being an efficient antioxidant with antinitridergic properties, has a promising role in the treatment and management of glaucoma. Melatonin could protect the ocular tissues against disorders like glaucoma, age-related macular degeneration, retinopathy of prematurity, photo-keratitis and cataracts [4].

  • However, melatonin secretion is inhibited by short or low quality sleep and by the ubiquitous blue-rich light exposure in the evening and night, hence for many people melatonin secretion starts as late as 90 minutes after falling asleep (i.e. 90 minutes after the last exposure to shorter visible spectrum wavelengths). As a consequence, melatonin has less time to function as an antioxidant in the body in general (which has been proved to result in higher cancer incidence) and also in the eye. When people are not exposed to blue wavelengths in the evening (e.g. by using firelight or dimmed incandescent bulbs or wearing red glasses) melatonin secretion starts roughly 90 minutes before sleep so melatonin has more time to do its antioxidant work.

My second question is about the relationship between macular degeneration and LED lights.

Could LED lights also increase the risk for macular degeneration?

  • Typically, LED lights (CCT = 4000 K) have a maximum peak at around 451 nm and a minimum in the 460-500 nm range (as is shown in their spectral power distribution of such LED lights below).

  • Melanopsin that controls pupilary reflex (pupil constriction), however, has maximum sensitivity around 479 nm - right in the LED spectral power distribution's (SPD) minimum. Could it be that due to this gap in SPD the pupil does not constrict enough and hence allows more of this blue rich light into the eye that as a result generates more free radicals and contributes to macular degeneration? Could this in combination with low sleep quality contribute to the onset of macular degeneration as LED (and lack of sleep) are widespread?

  • PS: I vaguely understood that at the moment it might be hard to answer some questions regarding melanopsin, but I am not sure how much it is related to my question. "It would be desirable to be able to quantify light as experienced by non-visual systems (melanopsin) using a single, one-dimensional unit (the equivalent of photopic lux). Achieving this for lights of divergent spectral content, however, awaits elucidation of a suitable spectral weighting function" [5]

Just How Safe Are LED Lights? Here’s Everything You Need to Know…

When it comes to any new technology – in any field, safety is always a primary factor to consider.

And despite LEDs having been on the market for decades now, there are still those who question their safety.

If you are one of them, this post is for you.

In it, we’ll discuss everything you need to know about LED lights safety and answer some of the most common questions people ask these days.

  • What effect do LED lights have on your eyes?
  • Are there any health problems that arise from LED light usage?
  • Should you be worried about fire hazards?
  • What is Blue Light and should you be worried about it?

Well, that’s what this in-depth review of LED lights safety is all about you’ll find answers to all these questions and more.

Is LED light Safe?

Blue-Light Hazard and LEDs: Fact or Fiction?

Ezume Images

Little is certain about the health implications of long-term exposure to LED lighting, but the proliferation of phosphor-coated white LEDs in everyday applications has sparked a renewed interest in research. Recent investigations have centered on the spike in the short-wavelength blue region of LEDs’ spectral power distributions (SPDs). Studies in disciplines outside of lighting have linked exposure to everything from circadian disruption to blue-light hazard, the latter of which this article will focus on. But should the general population be alarmed? Not really, say the lighting experts.

The Hazards of Blue Light
Blue-light hazard was discovered in the field of occupational health and safety in the 1970s, predating the invention of white LEDs. The term describes the acute photochemical damage to the retina caused by “staring at an intense light source,” such as a welding arc or the sun, says David Sliney, chairman of the IES Photobiology Committee. The radiation absorbed by the retina unleashes a series of chemical reactions that can lead to retinal inflammation, cell death, and white lesions within a day or two of exposure.

Research conducted over the last 40 years in medical academia has connected these phototoxic responses to short-wavelength radiation in the range of 400 to 500 nanometers—with a peak around 440 nanometers—prompting speculation about the safety of blue-rich light sources used in general illumination. Fluorescent sources also faced scrutiny for the blue peak in their SPDs, but as John Bullough, director of the Transportation and Safety Lighting Programs at the Lighting Research Center (LRC) in Troy, N.Y., explained in the Journal of the Illuminating Engineering Society in 2000, their low luminance makes any potential for risk of blue-light hazard “negligible.”

Photochemical damage from blue light exposure has also been implicated in age-related macular degeneration (AMD), a leading cause of vision loss in people over 65. Biomedical researchers suspect that long-term exposure to short-wavelength blue light can create oxidative stress on retinal cell structures, resulting in the accumulation of lipofuscin, a lipid-containing waste product that has been attributed to AMD.

Why So Blue?
Typical white LEDs consist of gallium nitride (GaN) and blue dye and a phosphor coating that converts a portion of the blue light into white. These phosphor-coated white LEDs can be fabricated with customized spectral profiles, but the process necessitates a spike in blue radiant energy. The phosphors produce a second, broader, and, in some cases, higher peak between 550 and 650 nanometers.

LEDs with correlated color temperatures (CCTs) topping 3000K are often singled out for their high blue content. In June, for example, the American Medical Association released a report cautioning against the use of high-CCT LEDs in outdoor applications, citing health concerns such as melatonin suppression and circadian disruption—which are technically distinct from blue-light hazard. Although CCT does correlate with a source’s blue-light content, the U.S. Department of Energy (DOE) states in its 2013 “Optical Safety of LEDs” fact sheet that the proportion of blue emissions in the spectrum “is not significantly higher for LEDs than it is for any other light source at the same CCT.”

The brightness of LEDs has also raised concerns. As a point source, the diodes emit a concentrated directional light that can be unpleasant to view directly. Still, their output is less than what the DOE cites as a risk for blue-light hazard: a luminance exceeding 4 gigacandela per square meter, and an illuminance exceeding 400,000 lux. Moreover, in interior lighting applications, the sources are often diffused, mitigating any discomfort.

Studies in Blue
The 1976 Nature article “Retinal Sensitivity to Damage from Short Wavelength Light,” by William Ham Jr., Harold Mueller, and David Sliney continues to be the go-to reference in contemporary research on blue-light hazard and AMD. Undertaken to differentiate between thermal and photochemical injuries caused by short-wavelength light, the study established minimum thresholds for damage by irradiating the retinas of anesthetized monkeys with lasers at wavelengths between 442 nanometers and 1,064 nanometers. Exposure periods ranged from 1 second to 1,000 seconds.

In his literature review, Bullough notes that the researchers determined “light at 442 nanometers was 100 to 1,000 times more damaging than energy at 1,064 nanometers” and that the lesions produced by the former seemed chemically induced while those inflicted by the latter were burns. This and a subsequent study by Ham formed the basis for the safety guidelines by the International Commission on Non-Ionizing Radiation Protection on protection against laser radiation, as well as for ANSI Z136.1-2007: American National Standard for Safe Use of Lasers.

Similar laboratory experiments also observed photochemical retinal damage associated with intense short-wavelength radiation. In a 2011 literature review in Photochemistry and Photobiology, Dutch researchers Dirk van Norren and Theo G.M.F. Gorgels examined 56 such papers, the most recent of which were published in 2009 and 2010, involving the directing of light from multiple sources into the retinas of live monkeys, rats, rabbits, or squirrels for a period of time, ranging from one second to five hours.

Extrapolating lighting recommendations from research can be tricky. In the 2014 post “Blue Light Hazard … or Not?” on the blog All Things Lighting, Ian Ashdown, chief scientist for Lighting Analysts and president of Vancouver-based ByHeart Consultants, notes that the light intensities used in much of the research to date were often too high to be instructive in determining health risks from long-term exposure. While the studies demonstrate that “both ultraviolet and blue light can permanently damage the retina if focused onto a small spot,” he says in an email to architectural lighting, “the exposure time necessary to do damage was equivalent to staring at the tropical noonday sun for 15 minutes without blinking.”

The Problem with Pinpointing LEDs
Excessive light levels have plagued similar studies on LEDs. In “Photoprotective Effects of Blue Light Absorbing Filter Against LED Light Exposure on Human Retinal Pigment Epithelial Cells In Vitro,” published in 2013 in the Journal of Carcinogenesis & Mutagenesis, the researchers subjected cultured, human retinal cells to intensities of 5mW per square centimeter of white, blue, green, and red LED light in three 12-hour on–off cycles, with and without a blue-light-absorbing filter. Although the filter did prevent phototoxicity from LED lighting, Ashdown says that the light exposure used on the cells was “hundreds of times more light than the human retina would be exposed to from LED light sources.” Moreover, because the experiment was done with cultured cells, it did not factor in the ability of a human’s “biological system” to repair cellular damage.

Even when researchers have attempted to approximate real-world applications of LEDs, a lack of lighting expertise has led to uncontrolled experimental conditions. In a 2014 paper in Environmental Health Perspectives, researchers exposed albino rats in cages to light from a blue LED, 6500K white LED, a 3000K yellow compact fluorescent lamp (CFL), and 6500K white CFL in 12-hour on–off cycles for up to 28 days. Although the light sources had verified SPDs and intensities, they were set 20 centimeters away from the rats and measured for 750 lux, exposing the rats to “completely different levels of blue light,” Ashdown says. Furthermore, the light levels far exceeded what the rodents, which have light-sensitive retinas, encounter in reality. While blue-light-induced retinal damage was found, he notes, this study was flawed.

In fact, Ashdown, who has studied solid-state lighting and its impact on human vision since 1999, says that not one academic paper associating blue light with retinal injury “presents credible evidence that light levels encountered in everyday life will cause retinal lesions.”

The real issue, says Robert Clear, a retired staff scientist with Lawrence Berkeley National Laboratory and a sitting member of the IES Roadway Lighting Committee, is that this topic requires “an intersection of two sets of expertise. The people who are knowledgeable in biology are generally not familiar enough with lighting to be able to evaluate it.”

In epidemiology, the findings are even slimmer. Few studies have demonstrated the health effects of long-term exposure to blue light or yielded evidence of a connection to increased risk for AMD. “Maybe one out of 20 will show there’s a possible linkage,” Sliney says. An often-cited example is Hugh Taylor’s study of 838 Chesapeake Bay fishermen chronically exposed to sunlight, published in Transactions of the American Ophthalmological Society in 1990, which found only a marginal association.

Going Beyond Blue-Light Hazard
Considerable research has focused on the impact of short-wavelength light on the eye’s functions unrelated to vision, such as melatonin and circadian regulation. Although light exposure in general can inhibit the release of melatonin, the hormone that signals to the body the onset of darkness or night, studies have shown that blue light seems to exert a more powerful effect. For example, boosting light levels and color temperature for 30 to 45 minutes has helped astronauts feel more awake, says Stan Walerczyk, principal of San Francisco–based Lighting Wizards, an energy-efficiency consultancy.

Other evidence suggests that nocturnal use of LED-lit mobile devices and computer displays, which emit a bluish cast, can delay sleep. Walerczyk recommends avoiding “blue light one to two hours before you go to bed.” For those who can’t stay away from their screens, free apps such as F.lux will increase and decrease the blue component in an electronic display according to the time of day, he says. Apple also offers a “night shift” option in its mobile devices that casts a hue atop screens during evening hours.

In outdoor applications, such as street lighting, LEDs with higher amounts of blue light could potentially suppress melatonin production, as the June AMA report alleges. However, the DOE and the LRC, in their responses to the AMA report, note that any conclusions to be drawn need to factor in the amount and duration of light exposure.

Avoidance Strategies
Despite the vast amount of research conducted on blue-light hazard and other blue-light-related health issues, much remains unknown about the health implications of the chronic exposure to LED light at levels encountered in daily life. However, based on a host of current international standards, such as CIE S 009-2002: Photobiological Safety of Lamps and Lamp Systems and ANSI/IES RP-27: Recommended Practice for Photobiological Safety for Lamps and Lamp Systems, the DOE has found no risk of blue-light hazard in LEDs or any other source used in general lighting applications.

All of this is not to say that the brightness of LED lighting and its blue content pose no harm to certain segments of the population, such as infants who might not avert their eyes frequently enough from light sources, and people with AMD and other eye disorders.

For the general population, Walerczyk says, “it is important to have sufficient 460 to 490 nanometers—which some people just call 480 nanometers—of light most of the day.” The best way to check an LED light source’s blue emission, SPD, and light output, he says, is to invest in a spectrometer and “skip CCT and CRI.” •

Select Resources

“The Blue-Light Hazard: A Review,” by John Bullough, Journal of the Illuminating Engineering Society, 2000.

“Optical Safety of LEDs” fact sheet, U.S. Department of Energy, 2013.

“Retinal Sensitivity to Damage from Short Wavelength Light,” by William T. Ham Jr., Harold A. Mueller, and David Sliney, Nature, 1976.

“SSL Postings: LED Street Lighting,” by the U.S. Department of Energy, June 21, 2016.

About the Author

An independent writer and editor, Alice Liao has covered the building and design industry for more than 15 years. She is a former editor of Architectural Lighting and Kitchen & Bath Business. Her articles have appeared in several publications, including EcoStructure, SNAP, and Hamptons.

What Makes Near-Infrared so Special?

You cannot feel near-infrared as heat, and you cannot see it, but it has a major beneficial impact in terms of health. Near-infrared is what’s missing in non-thermal artificial light sources like LED.

There’s also a difference between analog and digital forms of light sources, and this difference is another part of the complexity. In essence, there are two separate but related issues: the analog versus digital light source problem, and the spectral wavelength differences.

Starting with the latter, when you look at the rainbow spectrum, the visible part of light ends in red. Infrared-A or near-infrared is the beginning of the invisible light spectrum following red. This in turn is followed by infrared-B (mid-infrared) and infrared-C (far-infrared). While they cannot be seen, the mid- and far-infrared range can be felt as heat. This does not apply to infrared-A, however, which has a wavelength between 700 and 1,500 nm. Explains Wunsch:

“Here you have only very low absorption by water molecules, and this is the reason why radiation has a very high transmittance. In other words, it penetrates very deeply into your tissue, so the energy distributes in a large tissue volume. This near-infrared A is not heating up the tissue so you will not feel directly any effect of heat. This significantly changes when we increase the wavelength, let’s say, to 2,000 nm. Here we are in the infrared-B range and this already is felt as heat. And from 3,000 nm on to the longer wavelength, we have almost full absorption, mainly by the water molecule, and this is [felt as] heating.”

The Effects of Blue-Light Exposure on Your Health and Sleep

Times have changed. Up until the advent of electrical and other types of artificial lighting, people mostly engaged in activity during daylight hours. Hours of wakefulness after dark were relatively short and spent in ways conducive with winding down and preparing to sleep. Light exposure after sundown consisted of the glow of amber hues from candles, oil lamps, and campfires.

This life pattern was compatible with the body’s natural sleep/wake 24- hour cycle known as circadian rhythm. Our bodies were designed so that light and darkness act as signals to regulate the proper balance between times of wakefulness and rest. Daylight’s bright blue-light wavelengths from the sun let the body know it is time to be awake and alert whereas darkness cues it to release the hormone melatonin that helps us begin to feel ready for sleep.

In today’s world, we are surrounded by the brightness of man-made blue-light wavelengths at all times of the day and night due to artificial lighting (particularly LED and fluorescent lights in addition to incandescent and halogen) as well as from the screens of TV’s, computers, smartphones, and other electronic devices.

Blue light is the part of the visible light spectrum with the shortest wavelengths and highest energy. Its wavelengths are detected by specialized photosensitive receptors in the retina of the eye that then transmit information to cells within our internal master clock (known as the SCN – Suprachiasmatic Nucleus) located in the hypothalamus area of the brain. This not only determines the light-dark cycle of a 24 hour period but also affects various rhythms and functions of the body as “clocks” within the body’s cells synchronize with the master clock.

When it is dark, stimulation from these forms of blue lightwaves that normally only occur during the brightest hours of the day can throw off our body’s internal clock and upset the natural rhythm that triggers sound sleep, waking, hunger, hormone secretion, cellular function, and gene expression. Particularly disruptive to sleep quality is the fact that activating this area of the brain with blue lightwaves prevents the pineal gland from producing melatonin, a hormone that induces drowsiness and promotes natural sleep cycles. Artificial blue light basically tricks your body into thinking it is daytime when it is actually night.

Blue Light Effects on Melatonin Production and Sleep Quality

Blue light wavelengths disturb natural sleep patterns and result in poor sleep quality due to the suppression of melatonin levels that should normally rise after dark and reach peak in the middle of the night when REM sleep typically begins. Experiments conducted by Harvard researchers that compared blue light exposure to green light of similar brightness concluded that blue light suppressed melatonin and shifted circadian rhythms twice as much. Even the American Medical Association recognized in 2016 that streetlights with blue-light rich LED lights significantly suppressed melatonin at night and impacted circadian sleep rhythms five times more than conventional street lamps.

Intense blue light from TVs, smartphones, and computers have been shown to inhibit melatonin production in the brain up to 80 percent. Sleeping with a light on can decrease melatonin levels by as much as 85 percent. A study published by the Journal of Clinical Endocrinology and Metabolism revealed that exposure to room light before bedtime resulted in delayed release of melatonin in 99 percent of study participants and reduced the duration of melatonin release by about 90 minutes.

Melatonin is not only important for helping to induce deep quality sleep but is also a powerful antioxidant hormone that works during the night to remove the effects of free radicals that can cause cellular and DNA damage and, ultimately, disease. It is also essential to the regulation of the energy powerhouses of our cells (mitochondria) and helps prevents oxidative stress that leads to mitochondrial dysfunction.

Health Effects Associated with Nighttime Blue Light Exposure

Sleep is not the only thing to suffer when our internal biological clock is thrown out of sync. According to Dr. Joseph Mercola, “exposure to artificial light at the wrong times of day is one of the largest often-overlooked health risks of living in the 21st century.” A 2016 study published in Current Biology revealed that mice exposed to continuous artificial light for five months experienced ill effects on their health that included inflammatory activation of the immune system, muscle loss and signs of osteoporosis. Within a period of two weeks after restoring their natural light-dark cycle, the mice rapidly returned to normal function. Researchers concluded that disrupted circadian rhythm can trigger detrimental (howbeit reversible) effects on multiple biological processes.

Chronic Diseases – a number of studies suggest a link between too much exposure to light at night (such as with nightshift workers) and greater incidents of heart disease, diabetes, obesity, and certain types of cancer. In 2007, the World Health Organization classified shift work as a ‘probable carcinogen’ after various studies substantiated the fact that light at night increased the risk of breast cancer. A clear association between reduced melatonin and a variety of cancers has been observed in studies as well.

Metabolic Health – an individual’s metabolic health along with their risk of becoming obese and/or developing Type 2 diabetes is also linked with the body’s internal master clock impacted by disturbances in circadian rhythm. Lower melatonin levels are independently associated in studies with the risk of developing type 2 diabetes. Participants in a Harvard Medical School study who were placed on a different schedule that shifted their circadian rhythm experienced increases in blood sugar that put them into a prediabetic state. At the same time, their leptin levels decreased (leptin is a hormone that lets the body know it is full after a meal is consumed). It is known that fat burning increases during the dark phase of our body’s biological clock and light detection shifts the body out of fat-burning mode into a sugar-burning state. Consequently, too much blue light exposure that disrupts circadian rhythm results in a greater tendency to put on pounds.

Mood and Psychological Disorders – disturbances in sleep due to inhibition of melatonin production and out of sync circadian rhythm cycles from blue light exposure play a significant role in the onset and continuation of mood disorders such as depression, bipolar disorder, generalized anxiety, and post-traumatic stress disorder. Studies repeatedly show that people who do shift work are more likely to suffer depressive episodes with a risk of major depression if shift work continues over a period of many years.

Eye Health – blue light is also detrimental to eye health and increases the risk of macular degeneration. Since virtually all blue light rays pass through the cornea and lens and reach the retina, damage can easily occur to light-sensitive cells in the retina that can lead to permanent vision loss. Digital eye strain results from looking too much at screens with blue light. The reason is that it becomes more difficult to focus due to the fact that short-wavelength, high energy blue light scatters more than other light wavelengths.

Ways to Protect Yourself from Blue Light after Dark

There are a variety of ways you can reprogram your body’s inner clock to distinguish between evening as a time for sleep and daytime as a time to be awake and energetic. To experience better sleep and protect your health at the same time, consider implementing the following recommendations:

  • Blue light-blocking glasses – a simple and relatively inexpensive way to block blue light when exposed to artificial light at night is to use orange/amber tinted blue-light-blocking glasses which you can easily find on Amazon. Not only will these glasses filter out blue light but they also prevent damage to DHA (an essential fatty acid) within the lining of retinal cells that convert sunlight into important electrical impulses sent to the brain. In studies conducted with nightshift workers at high risk for disorders associated with circadian rhythm disturbances, those who used blue-light-blocking glasses during the latter part of their shift for a period of weeks experienced overall increased sleep and sleep quality.
  • Blue light filtering software/apps – if you will be exposed to screens from a computer at night, install the
    free software from flux that adjusts a display’s color temperature according to location and time of day, filtering out blue wavelengths after sunset. In addition, many laptops, smartphones, and tablets now provide blue-light shield options that also filter out those wavelengths (known as “night mode” on Apple devices).
  • Avoid or greatly reduce artificially lit screens after dark or at least within 1-2 hours of bedtime – this would include TVs, tablets, e-readers, smartphones, and other devices that emit blue lightwaves. If you do need or choose to use these devices during that period of time, utilize blue-light-blocking glasses or other blue light-blocking measures. Keep in mind that reading with a dim lamp is a much better alternative to spending time in front of these screens, especially in the hour or so before you head to bed.
  • Use dimmer lighting at night – turn off overhead lights and keep lamps as dim as possible once it gets dark. If you cannot dim lights, you can use special amber light bulbs (also available on Amazon) that emit a different frequency of light that will not interfere with your circadian rhythm. Use dim red lights for night lights as that hue is less likely to shift circadian rhythm and suppress melatonin.
  • Sleep in complete darkness, or as close to it as possible – do whatever you have to do to ensure your bedroom is pitch black at night as even the tiniest bit of light in the room can suppress your melatonin levels and disrupt REM sleep. Use room darkening or blackout shades, cover any lights from TV or cable boxes with electrical tape or dark material, close your bedroom door, get rid of night-lights and remove clocks from view (clocks with blue or green digital lighting should not be used in a bedroom unless they are covered at night. While red light is less of a problem, the clock should be turned so that the light faces away from you). If you must get up during the night, refrain from turning on a light and use a dim flashlight or other low non-white or blue light if you must see to find the bathroom.
  • Wear a sleep mask – if you are unable to completely follow the recommendations in the previous step or if you are in an environment that you cannot control when away from home, wear a sleep mask to block out surrounding light.

The Benefits of Daytime Blue Light Exposure

Along with taking steps to block nighttime blue lightwaves, an equally important way to maintain a balanced circadian rhythm and promote better health and sleep quality is to avail yourself of regular exposure to daylight, especially within the first two hours of waking for at least 20 minutes (gazing directly at the sun is not necessary nor recommended but eyes should not be shielded by sunglasses, glasses or contact lenses). These bright blue light wavelengths from the sun are very beneficial and provide a type of full spectrum illumination unobtainable with most artificial lighting. Outside light is far more intense in lux units than indoor light. The latter is generally 100-500 lux units in comparison to approximately 100,000 lux units of outside light at midday. Even if it is overcast, the lux of natural sunlight far exceeds artificial light.

Sunlight exposure also stimulates the manufacture of vitamin D, a hormone that boosts immune function, strengthens bones and muscle and helps to prevent cancer, dementia, metabolic and other diseases. Moreover, it increases production of serotonin needed for sufficient secretion of melatonin at night. Higher serotonin levels help keep energy levels up, boost mental focus and attention span, speed reaction times, reduce daytime sleepiness, and improve mood. Even short exposure to sunlight will allow you to sleep more deeply at night due to the greater contrast with darkness that works to signal increased melatonin production (keep in mind that staying inside all during the day can decrease your melatonin at night by half!) Direct exposure to bright natural light also triggers the body to produce a spike in morning cortisol that works in conjunction with melatonin to regulate the sleep-wake cycle.

For times when bright morning sunlight is not available, some health experts recommend using light therapy boxes that emit bright blue wavelengths that mimic the role sunlight plays in stimulating optimal serotonin production and cortisol rhythm. These types of light boxes generally give off 10,000 or more lux light and are often used to treat SAD (Seasonal Affective Disorder), a type of depression that is more prevalent in the winter when daylight hours are shorter. Both natural sunlight and similar brightness from a light therapy box work to promote greater energy, mood and sleep quality.

While the pivotal introduction of electric light to society occurred nearly 140 years ago, only in recent years are scientists learning the true effects of artificial light at night on the brain and body. If you would like to learn more about this subject along with further information on strategies that can help you minimize night exposure to blue light and subsequent risks to your health and well-being, I would encourage you to check out the internet articles I have listed below.

Lamp Types and Health Risks

Danger of LED Lightbulbs

Flicker. Because LEDs are digital lights, they flicker. Most people cannot perceive this. Color-changing LED lights and dimmed LED lights turn completely off and completely on, very quickly. Flicker is “biologically active. And flicker is something that is very harmful to your [biology],” according to Dr. Alexander Wunsch, an expert on photobiology. 8 Old TVs had noticeable flicker modern flat screens still have flicker, but it is much faster.

Blue Light. LED lights emit substantial amounts of blue light, and their emission of light is high intensity. Researchers in France wrote that these factors “are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina.” 9 They conducted a peer-reviewed animal study. After exposing rats to commercially available white LEDs and four kinds of blue LEDs, they examined the animals’ retinas. They discovered that the lights caused oxidative damage, injury and cell death to the retinal cells and photoreceptor cells.

Toxins: Although LED lights do not contain mercury, they do contain lead, arsenic and a number of other toxins and heavy metals. The low-intensity red LEDs were found to contain up to 8 times the safe levels of lead. 10

Danger of Florescent Lightbulbs

Wavelength. May interfere with circadian rhythms due to suppression of melatonin, which in turn has been linked to cancer. Warm white does this the least, and so is recommended for night time use.

Flicker. May cause problems for people who are sensitive to light, such as 21% of people with chronic fatigue or Lyme disease. Some newer lamps have less flicker problems.

Ultraviolet light. The ‘double-envelope‘ compact fluorescents, which look like a regular light bulb, are ok. But exposure over an hour to unshaded ‘single-envelope’ compact lamps can exceed radiation guidelines. These are the bulbs that show the spiral shaped bulb. 3 to 6 hours exposure daily is equivalent to a 10% to 30% exposure to carcinogenic radiation.

In addition, in product safety testing, some of these single-envelope CFL’s were found to have cracks in the phosphor coating – which might permit UV leakage. Avoid this by buying only double-envelope CFLs. 11

Eye Harm. Cataract risk is increased by exposure to ultraviolet light. But provided lamps are a safe distance (more than 30 cm), there should be little increased risk.

Electromagnetic risk. The electronic ballasts emit electro-magnetic fields in low frequency range and have been classified as possibly carcinogenic. Bulbs with high frequency ranges pose more risk, but again, not being too close makes a difference.

Mercury. Always follow safety guideline for cleaning up and disposing of fluorescents since they contain mercury. The amount of mercury is small compared to, for example, a single dental amalgam filling.

Other. There are anecdotal reports, but insufficient research connecting fluorescents and compact fluorescents with other conditions like migraines and autism.

Eye, Sleep and Skin Effects

It is well established that eye structures are harmed by exposure to solar UV radiation. Points De Vue 2017. That is why ophthalmologists and optometrists advise wearing UV protective sunglasses when outdoors. Newer research is now demonstrating a host of serious risks associated with exposure to digital screens, blue light and radiofrequency radiation from wireless devices. The American Academy of Ophthalmology is concerned that too much screen time is now affecting children’s vision, including myopia and dry eye symptoms. Retinal phototoxicity from blue light is now established as a risk. Sleep and human circadian sleep disruption by blue light is considered essentially proven by health authorities. Increased screen time is now identified as a risk factor for dry eye syndrome and computer vision syndrome. Research has also revealed damage to skin from radiation from digital screens as well.

Researchers are concerned as our exposure to artificial blue-rich lighting is almost constant. The number of commercial products using blue lights has mushroomed and includes not only screens we stare at all day and night but also commercial products such as decorative string lights and toys which have bare LEDs. Even short exposures can have disruptive effects,

Skin is Vulnerable

The skin is the largest organ of the body and vulnerable to injury from many environmental factors. We are well informed about the dangers of UV exposures from the sun and suntanning booths, which can cause skin cancers, loss of skin elasticity and aging. Arjmandi (2018) spotlights the lesser known hazard of blue light, emitted from light emitting diodes (LED) screens, on skin. He describes the known mechanism of oxidative damage to the skin from exposure to both UV radiation, and the more recent addition of LEDs to our environment.

LED lights are widely used on cell phones, laptops, tablets, televisions and overhead lighting, in the effort to save energy. We now get almost constant exposure to blue light while we are awake day and night and both indoors on screens and outdoors on streetlights. In reviewing the literature on blue light harm in his article, “Can Light Emitted from Smartphone Screens and Taking Selfies Cause Premature Aging and Wrinkles?“, research shows the answer is yes, and with just one hour of screen time at 1cm. We hold the phone closer than that on a call. He underscores that the effects of long term and intermittent exposures to skin are not known.

Screen Use and Acne

Published papers report that in vitro (lab experiments) blue light kills skin bacteria. While researchers are hopeful it will be used as phototherapy for acne, Taheri (2017) used the actual cell phone screens to see what they would do to staphylococcus aureus, a common acne bacteria. His group found, for the first time, that exposure to tablet and smartphone screen radiation significantly increased the rate of growth of staphylococcus bacteria and the maximum growth was at 300 minutes of exposure. It is possible that there is a combination of factors involved, as Sid- Salman (2019) found that a Wi Fi router increased antibiotic resistance and motility of E Coli and increased metabolic activity and biofilm production in Staphylococcus Aureus and Staphylococcus Epidermis.

Eyes Are Vulnerable

The eyes are uniquely vulnerable as they have no outer protective layer. Studies demonstrate cumulative damage to the cornea and lens of the eye with long-term UV/sunlight exposure (noted above) and now evidence is also pointing to blue light and non-ionizing radiation from wireless devices as causal agent for cataracts with a similar mechanism of oxidative damage.

Blue Light, Retinal Damage, Insomnia and Chronic Disease

Published data is documenting that LED blue light from screens and lighting is a true risk for oxidative retinal damage and circadian rhythm disruption, as well as melatonin reduction causing sleep disruption. Sleep disruption (or chronic insomnia) can have a profound effect on our health, and is associated with a host of chronic diseases, including cancer, obesity, high blood pressure, heart disease, poor memory, depression and anxiety, as well as poor learning performance. Melatonin, an important internal antioxidant, also protects eye structures from oxidative damage from a variety of sources.

French Health Authority Publishes Expert Appraisal of Blue Light

In 2014 ANES, the French Agency for Food, Environmental and Occupational Health & Safety, convened a Working Group to assess the effects on human health and the environment of systems using light-emitting diodes (LEDs). Their goal was to measure current real life levels of blue light exposure of children, the general public and workers to blue light and then to assess risks. This was in response to policies developed to remove halogen and incandescent lighting to reduce energy consumption.

They found that blue light has phototoxic, circadian rhythm and sleep effects. Blue light produces more glare and there is also more variation in light intensity depending on the power supply.

ICNIRP Guidelines for Blue Light Are Obsolete

ANES noted that the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines published in 2013 for blue light were the same as those published in 1997 and involved only acute exposure and did not take into consideration that children’s eye are more vulnerable with more blue light entering the eye. More over there are no regulations for circadian rhythm disruption, glare or light modulation.

ANES Published Results 2019: Findings

  • The risk of circadian disruptionassociated with exposure to blue-rich LED lights in the evening or at night is high and likely to adversely affect sleep duration and quality and impact cognitive functions
  • Circadian rhythm disruption is a higher risk in infants, children, adolescents and young adults (due to a clear lens) pregnant women (potential health effects on the unborn child) night workers those with sleep disorders and possibly those with migraines
  • Professionals with potentially high exposure to LED lighting (surgeons, dentists, lighting professionals, lighting distributors, performing artists, people working in sport facilities, people working in agri-food facilities using LEDs (greenhouses, aquaculture), etc.) are at higher risk
  • The retinal phototoxicity of acute (for less than eight hours) exposure to blue-rich light is proven
  • The contribution of chronic (for several years) retinal exposure to blue-rich light (including sunlight) to the occurrence of ARMD is proven
  • Studies have shown that the exposure limits (ELs) selected by ICNIRP for the retinal toxicity of light are not sufficiently protective
  • The effect of blue-rich light on myopia is possible (whether positive or negative)
  • The effect of blue-rich light on the occurrence of Sjögren syndrome is possible

Cataracts on the Rise

There is a continued rise in the prevalence and incidence of cataract surgery which is attributed to better access and diagnosis, without consideration of ubiquitous environmental causes, such as increased screen time with blue light exposure. With children, whose systems are still developing and who are now exposed to screens at home and now mandated at school, there are even more serious concerns.

Computer Vision Syndrome and Dry Eye

Computer Vision Syndrome (CVS) is an increasingly recognized but an under-diagnosed syndrome resulting from prolonged screen time with video display terminals (computers, laptops, tablets, cell phones). Symptoms include include headache, eyestrain, tired eyes, irritation, redness, blurred vision, and double vision. Dry eye symptoms often accompany CVS with reduced blinking rate and increased corneal exposure. There is evidence that atrophy of the lubricating meibomian glands around the eyes are involved as well. Researchers warn that people spending more than 4 hours a day at the screen are at major risk to develop dry eye symptoms and computer vision syndrome. It is estimated that 50 to 90 % of students and those who use computers at work experience this. The American Academy of Ophthalmology has recommendations to reduce eye strain with the use of digital devices.

Eye Strain

Using cell phones and tablets at close distances to view movies or read for long periods causes eyestrain. A study by Long (2017), Viewing distance and eyestrain symptoms with prolonged viewing of smartphones of young adults using a cell phone for 60 minute to read showed a significant increase in eye strain, with students reporting tired eyes, uncomfortable eyes and blurred vision. Another study by Antona (2018), Symptoms associated with reading from a smartphone in conditions of light and dark showed significant eyestrain from using a smartphone for prolonged periods versus a hardcopy, especially if the smartphone was used in the dark.

The 20-20-20 Vision Rule

Staring at screens from computers, cell phones, gaming, tablets and television for long periods of time can cause eye fatigue and computer vision syndrome with blurred vision tearing, and headaches. To reduce eye strain it is recommended to use the 20-20-20 rule: Every 20 Minutes look at something 20 feet away for 20 seconds. It is also recommended to:

  • Position your screen an arms length away from your eyes and at 20 degrees below eye level
  • Alternate from looking at your screen to looking at paperwork and your surroundings
  • Match the brightness of your screen with surroundings
  • Remember to blink. When we are not on the computer we blink 12 times a minute but when on the computer we blink only 5 times a minute
  • See a physician if you have symptoms of computer vision syndrome
  • Consider a low blue light computer shield or low blue light glasses from a reputable company that reduce blue light.

China Bans Digital Screens in Classrooms to Prevent Eye Damage

Because of the growing evidence for the risk of eye damage from digital screens and research showing an association with myopia, China has banned cell phones from classrooms. See China Bans Smart Phones in Schools . The Ministry of Education and the National Health Commission has banned the use of cell phones and tablets in classrooms in Shandong province and asked parents and teachers to:

  • Not rely on electronic devices for teaching and assignments and use written assignments
  • Limit children’s use of electronic screens not more than one hour a day and not exceed 15 minutes in a single session
  • Keep proper distance from eyes and screens
  • Have correct reading positions
  • Have sufficient backlighting

Retinal Oxidative Eye Damage and Blindness From Blue Light

Researchers from Sweden in 2006 reviewed the pathogenesis of age-related macular degeneration. In their paper looking at light damage, Age-related maculopathy and the impact of blue light hazard, they note that oxidative stress and free radical formation cause damage to cellular structures in the retina, leading to inflammation and lipofuscin deposition. They recommended antioxidants to slow age-related macular degeneration, which is more common after the age of 60.

University of Toledo scientists in the Department of Chemistry published a study in 2018 showing that exposure to Blue Light caused damage and death to photoreceptor cells in the retina. These photo receptor cells cannot regenerate, speeding up macular degeneration, which leads to blindness. Another 2018 study from Spain, Removal of the blue component of light significantly decreases retinal damage after high intensity exposure, demonstrated a 94% blue -blocking filter decreases significantly photoreceptor damage after exposure to high intensity light .

Osborne (2017) has researched the adverse effects of blue light on retinal mitochondria and found, “Neurones of the central nervous system have an absolute dependence on mitochondrial generated ATP. Laboratory studies show that short-wave or blue light (400–480 nm) that impinges on the retina affect flavin and cytochrome constituents associated with mitochondria to decrease the rate of ATP formation, stimulate ROS and results in cell death. This suggests that blue light could potentially have a negative influence on retinal ganglion cell (RGC) mitochondria”. Shang (2017), Aadane (2015), Shang (2014), Chamorro (2013) and Behar-Cohen (2011) are among others who have also demonstrated the serious oxidative effects of blue light from digital screens.

Research has shown that non-thermally related radio frequency radiation (RFR) can also cause ocular pathology and eye damage, with the creation of reactive oxygen species (ROS). This is an important consideration with exposure to wireless radio frequency radiation in 2G, 3G, 4G systems. It is an even higher concern for 5G proposed short millimeter wave technology, as this very short high frequency radiation has been shown to create more damage and higher heat concentration with use. Research on the adverse health effects on the eyes for 2G, 3G and 4G let alone 5G are severely lacking while wireless devices are increasingly being placed in close proximity to our brains and eyes. (Fernandez 2018, Sage 2018)

Blue Light from Digital Devices Blocks Melatonin, Sleep and Shifts the Circadian Clock

Researchers have now proven that use of digital devices at night such as cell phones, tablets, computers and TV’s with LED lighting and even overhead LED lighting, can interrupt sleep patterns as they emit blue light frequencies. Blue light hits receptors in retinal ganglion cells which sends a message to the suprachiasmatic nuclei of the hypothalamus, the seat of the central circadian clock. This retinal clock then sends the message to the rest of the body in order to synchronize all of the biological functions with the day/night cycle.(ANES) The secretion of the sleep signaling hormone melatonin by the pineal gland occurs only in darkness and is suppressed by blue light, thus altering the circadian rhythm.

West (2011) demonstrated that the strongest melatonin response was between 446 nm and 477 nm. In a recent study by UCSF, Direct Measurements of Smartphone Screen-Time: Relationships with Demographics and Sleep. scientists concluded,”Longer average screen-times during bedtime and the sleeping period were associated with poor sleep quality, decreased sleep efficiency, and longer sleep onset latency.” A other recent study by Chindamo (2019), Sleep and new media usage in toddlers, found everyday use of a tablet or smartphone raised the odds of a shorter total sleep time and a longer sleep onset latency. Excess screen time is also associated with other health issues as described in this paper by Kenny(2017), United States Adolescents’ Television, Computer, Videogame, Smartphone, and Tablet Use: Associations with Sugary Drinks, Sleep, Physical Activity, and Obesity.

Circadian Shifts With Blue Light

A Harvard study found that blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much as green light. The circadian shift was 3 hours for blue light and 1.5 hours for green light.

A study by Chang (2015), Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness, demonstrated that these LED devices can shift our natural sleep clock. The researches compared 2 groups of participants. One group read an e-book with LED (peak 450nm) lighting 4 hours before bed and the second group read a printed book again 4 hours before bed. In the e readers they found lower melatonin levels, less REM sleep and after 5 days they demonstrated a 1.5 hour phase shift in circadian clock., thus it took longer for them to fall asleep. Although at night the e readers were more alert, in the morning they were less alert. The researchers conclude, “Our findings provide evidence that the electric light to which we are exposed between dusk and bedtime has profound biological effects.”

Unborn Babies at Risk From Blue Light

Although blue light does not directly reach the fetus, scientists have found that the maternal reduction in melatonin, a potent internally produced antioxidant, may affect fetal neurodevelopment and be associated with autism spectrum disorder (ASD) (Jin 2018). Studies have shown that melatonin is a critical hormone that is neuropcrotecive in ASD and also protects from DNA damage.(Braam 2018)showed that melatonin “levels were significantly lower in mothers with an ASD child.”

Reiter (2013) notes that melatonin serves and important role in reproduction.”Melatonin is a multifaceted molecule with direct free radical scavenging and indirect antioxidant activities. Melatonin is produced in both the ovary and in the placenta where it protects against molecular mutilation and cellular dysfunction arising from oxidative/nitrosative stress….Optimal circadian rhythmicity in the mother is important since her circadian clock, either directly or indirectly via the melatonin rhythm, programs the developing master oscillator of the fetus.” Disrupted melatonin cycles are associated with disturbances in behavior in the newborn.

Hsu (2020) reviewed the literature and concludes that reduction in maternal melatonin could affect signaling pathways, predisposing the fetus to a number of adult chronic health conditions. They describe the critical role that melatonin plays in development. Melatonin receptors are present in many tissues in the human fetal brain. Although the fetal pineal gland does not secrete melatonin until after birth, maternal pineal melatonin does cross the placenta. Maternal light signals thus can be transferred to the fetus. The biological clock is run by a complex system of molecular signals affecting transcription and stress pathways. The authors note, “Placenta-derived melatonin acts as an autocrine, paracrine, and endocrine hormone in a non-circadian fashion…Placenta-derived melatonin not only acts with the MT1 and MT2 receptors but also directly scavenges free radicals, which reduce oxidative damage to placental tissues.”

French Agency for Food, Environmental and Occupational Health & Safety on LED Lights 2019

ANES, the French Agency for Food, Environmental and Occupational Health & Safety published an extensive independent report on the “effects on human health and the environment (fauna and flora) systems using light-emitting diodes (LEDs).

They noted, Over the past few decades, humans have considerably increased their exposure to blue light in the evening with artificial lighting and backlights rich in blue light… the Working Group’s experts consider that the risk of circadian disruption associated with exposure to blue-rich LED lights in the evening or at night is high. In particular, exposure before bedtime to LED lighting or screens from televisions or communication technologies enriched with blue light is likely to adversely affect sleep duration and quality and impact cognitive functions.” Their 2019 report is here- 5G ANSES French Study Blue Light 2020.

Doctors Warn That LED City Street Lights Blue Spectrum Can Cause Sleep Disruption

In 2016 the American Medical Association warned cities that the new energy efficient street light that were being installed to combat global climate change can harm the retina, affect circadian rhythms and sleep patterns. Studies have shown that brighter residential nighttime lighting is associated with sleep disruption. AMA Board Member Maya A. Babu, M.D., M.B.A states, “Despite the energy efficiency benefits, some LED lights are harmful when used as street lighting, The new AMA guidance encourages proper attention to optimal design and engineering features when converting to LED lighting that minimize detrimental health and environmental effects.”

News on Harm From LED Street Lamps

  • AMA Adopts Guidance to Reduce Harm from High Intensity Street Lights. June 2016.
  • Doctors issue warning about LED streetlights. June 2016.
  • Hidden Blue Hazard? LED Lighting and Retinal Damage in Rats. Environmental Health Perspectives 2014.
  • Do ‘environmentally friendly’ LED lights cause BLINDNESS? 2013.

Blue Light Blues: Melatonin Suppression and Breast Cancer

Blue light emitted from LED screens from computers, cell phones and tablets can inhibit melatonin production and alter circadian rhythms. Melatonin is a potent antioxidant, produced in the pineal gland, and is also found in the retina where it modulates genes responsible for circadian rhythms via the ganglion cell layer (Blasiak 2016). Researchers have found photosensitive retinal ganglion cells (ipRGCs) in the mammalian brain which are not related to image formation but direct circadian rhythms, pupil constriction and alertness through 465nm blue light Vandewalle(2018).

This cascade of biological effects contributes to a host of chronic disease states, including high blood pressure, depression and cancer.

Dr. David Blask and colleagues have conducted a series of studies showing that light suppresses melatonin leading to stimulation of breast cancer growth. When they grafted human MCF-7 breast cancer cell xenograft on mice and exposed one to light- light and the other to light-dark environments they found the light- light group had increased cancer cell growth rates. (Blask 2002) The International Agencyfor Cancer Research (IARC) classified shift work that involves circadian disruption as a “probable carcinogen”. (IARC 2007)

Harvard Recommendations for Reducing Blue Light Exposure

LED lights from lightbulbs, computers, cell phones, video games and tablets emit blue light from the screen. Overhead LED lights that are now commonly used also emit more blue light than fluorescent light bulbs, and incandescent light bulbs emit the least blue light. Although much more energy efficient, LED lighting which has largely replaced incandescent in homes, businesses and street lights, may be creating a health risk through complex biologic effects on our melatonin levels and circadian rhythms. Here are the Harvard guidelines Blue light has a dark side. Updated August 13, 2018.

Protect yourself from blue light at night (Harvard 2018)

  • Use dim red lights for night lights. Red light has the least power to shift circadian rhythm and suppress melatonin.
  • Avoid looking at bright screens beginning two to three hours before bed.
  • If you work a night shift or use a lot of electronic devices at night, consider wearing blue-light blocking glasses or installing an app that filters the blue/green wavelength at night.
  • Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night, as well as your mood and alertness during daylight.

Blue Light Blocking Glasses for Improved Physical and Mental Health

Amber colored blue light absorbing glasses, computer and cell phone screen covers have been developed to block blue light from artificial LED lighting and screens, typically 2-3 hours before bedtime. More research needs to be done, however, scientists have found that using these blue light blocking devices may promote higher melatonin levels near bedtime thus reducing insomnia. Evidence is showing the positive effects on blue light blocking glasses not only on sleep quality and timing (Zebrine 2018 Eskai 2016 Burkhart 2009) but also potentially on symptoms of mania in those with manic depressive symptoms by acting as physiologic “dark therapy” not necessarily related to melatonin production (Shirahama 2018 Henriksen 2016). Quality varies with the amount and spectrum of blue light blocked by different glasses. If you are purchasing glasses it is important to get high quality tested glasses and know which frequencies are blocked either full blue light blockage (400-500nm), full blue green blockage (400-550nm ) or specific blue frequencies (i.e.480nm) . In general the more full blue light spectrum blocked the better it will enhance melatonin production. Consumer Reports-3 Blue Blockers Put to the Test

Apple has introduced “Nightshift” software into their new phones (OS9.3 and above) that reduces blue light at night. You can access by pressing Settings >Display&Brightness >NightShift and set it to the times you wish the display to reduce blue light. Some research from the Lighting Research Center has shown that this Apple setting may not help you sleep as much as anticipated as the brightness of the screen and excess mental stimulation may also be factors on melatonin levels.

The Importance of Blocking Blue Light Peaks for Oxidation as well as for Normal Melatonin Production

Blue light spans 400 to 500nm. Retinal damage is caused by the span of blue light from 400-500nm, as well as lesser damage from green light 500-550 nm. Peak blue light at about 430nm is known to cause the most oxidative damage with regards to age related macular degeneration (ARM) in studies. Melatonin reduction has been found at a peak of about 450nm. It is important for full protection of the eyes to have full blue light blocking from 400-500nm. Many products sold have a very narrow range of blue light blocking. It is important to be aware of which parts of the blue light spectrum are absorbed by blue light blocking barriers before you purchase the glasses other blue light blocking products.

Dr. Vicente-Tejedor and colleagues demonstrated protection from blue light damage with broad blue light blocking.

Excitation and metabolic cycle of rhodopsin depending on the use of the blue-blocking filter. Wavelengths of the spectrum from 400-500nm excite rhodopsin and generate toxic waste but also cause retinal degeneration. From “Removal of the blue component of light significantly decreases retinal damage after high intensity exposure.” Vicente-Tejedor (2018)

Dr. Charles Czeisler Discusses Broad Health Impacts of Poor Sleep

Charles A. Czeisler, MD, PhD, Chief, Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital, explains the critical impacts of sleep on brain function and physical health. He states that sleep is the third pillar of good health along with nutrition and exercise. Lowering blue light at night is component of healthy sleep. Dr. Czeisler , whose group has worked with astronauts to reset their circadian rhythms before going into space research, highlights the many bodily systems effected by insomnia including

  • Brain Detoxification
  • Cardiovascular
  • Immune System
  • Weight Gain
  • Insulin Resistance / Pre diabetes

Fatal Collision: Harm from Wireless Eyewear

A new 2018 paper, Fatal Collision: Are Wireless Headsets a Risk in Treating Patients?, highlights the potential bodily harm from wearing wireless headsets, augmented reality systems and glass-type eyewear. Co-authored by Cindy Sage, who is also co- author of the Bioinitiative Report, this review article reveals that these devices, are connected to the internet and have similar radiation (2.4 and 5GHz) to cell phones. An association has been identified between long term cell phone use and brain cancers on the same side of the head. There is also the concern for lack of concentration and distraction when using these devices, similar to cell phones. Damage to eye structures is an obvious concern.

These wireless devices are increasingly being used in medicine (google glass-type wearables) and by educators but no thought has been given to the harm from long term use. Children are seen in ads wearing wireless headsets for entertainment. It is the next best marketing and sales opportunity in technology. Sage and Hardell note, “using wireless glass-type devices can expose the user to a specific absorption rates (SAR) of 1.11–1.46 W/kg of radiofrequency radiation. That RF intensity is as high as or higher than RF emissions of some cell phones. Prolonged use of cell phones used ipsilaterally at the head has been associated with statistically significant increased risk of glioma and acoustic neuroma.” Studies are inadequate to determine safety of these wireless devices long term. There are to date insufficient protective guidelines for adults or children who are increasing using these devices for entertainment, in classrooms and therapeutically in medicine. Precautionary recommendations for use are needed.

Eye Absorption of Radiation from Cell Phones and Virtual Reality

A seminal paper Fernandez et al (2018) reveals that young eyes and brains absorb 2 to 5 fold more radiation than that of an adult. He cautions that we need to reexamine regulations and compliance with regards to these devices as testing uses a large adult male (SAM) . Dr. Fernandez also advises precautions proposed by the American Academy of Pediatrics, that young children should not use cell phones. This study indicated virtual reality type devices should also not be used by children. He urges wired connections to reduce children’s needless exposure to non-ionizing radiation. More research is critically needed in this area as widespread commercial use has already begun.

About E.M.Smith

68 Responses to superchiasmatic LED light insomnia

Thanks for the heads up on LED lights. I don’t have any at our place. I guess I get to head to NV to stock up on a few more incandescent bulbs. Given a recent “Tip” over at WUWT about CFL’s I think I’ll skip buying any CFL’s for awhile.

This is news to me. Doesn’t having melatonin problems lead to mental problems. I wonder what kind of lights the Colorado shooter has been operating under?

Unmentioned in things like the Columbine shooting and Colorado is that often there is a history of “issues” and the shooters were on prescribed AHDH or similar drugs that are known to cause things like suicidal thoughts… It’s not the guns that’s the problem, it’s the drugged up (by prescription) kids.

Melatonin is an important stuff in your metabolism (not just cognition but also things like cancer and similar antioxidant roles). Mess it up, bad things happen. But yes, we now can add “sleep deprivation from lighting issues” to the ways we are messing up our lives and bodies.

I bought a “lifetime supply” mostly for the dimmer circuits where CFLs are sucky. Then found the LEDs looked nice and dimmed well. Figured I’d “way overbought” as LEDs were working in places where only Incandescent were acceptable before. Now I’m back to “about the right inventory”….

As the spouse need some UV for the S.A.D. issue, it’s a bit of a feature (at low levels). Most of my CFL fixtures are metal anyway ( I like indirect lighting, so it is aimed at white walls and such mostly) with only a few being glass bowls (bath that’s an Incandescent on a dimmer) and Kitchen and table lamp / shades ( 2 in the living room and one in the bedroom. Of the three, 2 are incandescents on dimmers – one a 3-Way – and the other is a CFL but might go back to Incandescent now…)

FWIW, you can buy 50 / 100 / 150 3-Way bulbs still and put them in a place (3-Way on low) that mostly runs the 50 W element. When that burns out, you have a 100 W bulb for regular fixtures… Also available are 100 / 200 / 300 and 50 / 150 / 200 and some others. I run one of these in the bedroom to “Manufacture” 100 W bulbs for the Bathroom…

Use a dimmer and you can make an Incandescent last a decade or more. ( about 80% power). I have all my Incandescent bulbs on dimmers. I have a stock of 200 W “Utility” bulbs to be run on dimmers for 75 – 100 W worth of lumens for my “deep time” stash. Very inefficient but they will never run out when I reach that point… The 200 W are still available (as are “rough service” bulbs that are similarly long life and poor efficiency at lower temperatures…)

Halogen bulbs do not like being run on dimmers. Some can take a little of it, such as those that are presently sold as high efficiency via being run really too hot – dim them some and they are in the longest life range. Dim them a lot and they do not reform the element. Halogen bulbs run hot so the halogen gas can scavenge the tungsten from inside the glass bulb and redeposit it on the element. So if you run them on dimmers, run them on high every so often for a while… and only dim them about 20% to 25%. (Or at the Very Dim end where not much tungsten is evaporating from the element anyway…)

So really, we have just a couple of places where the CFL UV would be an issue. But we are not in those places long / much.

Still, something to keep in mind… Don’t put them in reading lamps right next to your face…

As usual Chiefio has come at a problem from an unexpected direction!

On a more mundane level, I started buying compact fluorescents back in the 1990s when the only source was Amway. I liked them so much that by the time they were being pushed in every hardware store I had very few incandescents left.

Dimmers don’t like fluorescents so I have a dozen incandescents still. As these fail they are being replaced by LEDs with a 7:1 energy saving.

Frankly, the only reason I use fluorescents or LEDs is to save money. Anyone with 6th grade math skills should be able to figure out how much money one saves this way. That governments in the Republic of Ireland and California feel it is necessary to criminalise the sale of incandescents strikes me a shocking intrusion on individual liberty. Wasting money is one of the great pleasures in life. Next they will be criminalizing the sale of single malt scotch and fine cigars.

The last time scotch was banned this country still repected its Constitution so the 18th Amendment was enacted. When the time comes for a national ban on incandescent lamps will our federal legislators have the decency to enact the 28th Amendment or will the head of the EPA simplify things by issuing an edict?

I recently paid $20 each for 1W, 18 Volt LEDs from CREE (Raleigh, North Carolina). Pretty expensive for a lamp that puts out one tenth of the light that a 115V LED costing $10 can produce. No I am not completely crazy. Living in Florida one needs emergency lighting. The last time the lights went out for an extended period my flashlamp batteries ran down in a matter of hours. The Cree LED runs for 35 hours in my Sears Craftsman worklights. The standard 18V, 0.6A XRM bulb uses

11 Watts compared to 1.3 for the LED replacement.

How about looking for a filter to notch out that 440-460 nm wavelength?
Might make the light a trifle yellower, but….

Extremely interesting stuff. It’s a bit like the 50hz fluorescent light flicker in europe that caused people to get stressed. Makes the case for incandescent as still being the best option. I tried several LED lights, i haven’t found one the was ‘natural’. They are all off in some way, i guessed it was because the light frequency is too uniform. We are not used to uniform light, like music it needs harmonics. Remember the very first cd players. The sampler was so perfect the music was completely stripped of harmonics making it sound harsh.

… Lettuce see how the testing goes. Sounds like a good solution
Heck, sounds like a supersolution.

In fact, a superchiasmatic-LED-insomnialicious solution.

Didn’t Disney write song lyrics like that one time .

( I too greatly prefer staying up late, going to sleep in the very early morning. And use blue screen savers and blue-tined sceen images as a backdrop.

EM – looks like I’ll have to find some filter material to notch out that 460nm wavelength. I’ve been using low-energy bulbs for a long time, and once LEDs became available I’ve been changing to them instead. The recent LEDs (3W units) are rated as 3000K colour-temperature, which seems to be achieved by a yellowish top-filter on the SMD LEDs. Maybe these are notch-filters – I can’t find any spectral specs for the bulbs. I don’t find problems sleeping at night, but various significant others do, so it’s worth the experiment to find what difference a filter can make.

INteresting! I hate the CFLs, and fortunately can still get Incandescent. so have not moved to either the CFLs or LEDs yet. But I do like the LED light – which as you noted, appears more white than the CFL.

I do not sleep through the night. I have not done so in over 10 years. So I am a lousy subject for testing. However, my wife does have problems. But before I do any experimenting on her, I will have her read your article and see if SHE wants to partake of it. If the Incandescent work better, I will be stocking up before the ban goes into effect nationwide.

Excessive exposure to blue light (on a year after year basis, as with those who work out-of-doors) contributes to the development of macular degeneration. Special sunglasses are available that reduce the risk.

I was about to send the above off when my mind tugged at me question about LEDs and mouse research. It has been done and the results were scary for me. Two hours exposure per day for ONLY TWO WEEKS resulted in significant reduction in the photoreceptor layer of the eye! Let us hope that the mouse is much more sensitive to this stressor than humans. I didn’t have the time needed to track down a research citation, but I’m sure it is out there. This blog touches on highlights.—LED/show/1771077

@E.M. You are absolutely right. It is better a mix of several wavelengths, the closer to natural light the better, instead of LEDs which, by its nature, its emission is rather a very selected spectrum.
This issue takes us to a wider subject: That of the undulatory nature of reality and the interactions between waves. Waves can be used to heal or to kill, so technicians cannot irresponsibly play with these without studying them beforehand. These laws, forgotten and anathematized by “consensus”, are well known by musicians. Haan: LOL!, trouble is that fungi and men breathe oxygen….so if it kills fungi it is very probable it kills us (if amount is enough- wattage-).
Not a joke: This reveals the urgent necessity of replacing our current Physics paradigm to one based on the UNIFIED nature of reality, which btw has existed everywhere except in academia.

@P.G. Specially those having a Kool-Aid taste…

FWIW, I want to mention that I sleep through the night when I take my dose of cod liver oil right before going to bed.

I have minimal exposure to LEDs.

I shun the CFLs at work and at home. When they installed the latest-and-greatest money-saving fluorescents at work, and I began having headaches and also discovered that the majority of our front-office staff had begun suffering stress-related symptoms, I switched them off in my office and brought in table lamps and incandescents. It’s not as bright in my office, but everyone who comes in comments on how restful and homey it is.

Color TV’s can have a lot of blue also. Computer running lights are frequently blue these daze, blue is trendy. It’s all over the place! Anyway, when my SO can’t sleep, she hits the couch with the TV on, so I’m not sure WUWT.

Oddly, I was buying compact fluorescents before they had that name too… The old PL style with a socket adapter for lamps and an outboard magnetic ballast that you put in the power cord. Got them from Real Goods ( who mostly sold them to off the grid types and regular hippies… which gives an indication about my leanings -)

By the time the political push for them had come along, I had most things that could take one already running high efficiency lighting. ( I was “Director of Facilities” in addition to Director of I.T. for a valley company for a couple of years. Developed an interest in all things lighting and even some sense of aesthetics… Was astounded one day to hear myself saying to our furniture vendor “I like the Jacquard Weave but do you have it in more of a periwinkle?”… )

At any rate, I learned all the good points and the bad points of the various kinds of lighting long ago, and realized that incandescents had some places where they were just “worth it”. Politicians and Political Activists are emotion driven and lack any sense of depth in problem solving, so inevitably make bad decisions (as they are shallow decisions…)

FWIW my solution to the same emergency lighting situation was to buy LED Maglight Flashlights. About the same cost as your LED bulb (at bulk discounters like Lowes and HomeDepot) and nicely portable. Make a nice club, too -) ( I particularly like the 4 cell “C” type as they are lighter and move faster.)

If you can find one, it would be a nice addition… but since the area under that chunk of the curve is a significant part of the total energy, your efficiency is going to have issues.

IMHO the better solution is the UV LED and a cleaner phosphor mix OR use 3 LEDs in RBG with the blue a bit on the lower power side. (Though that gives three color spikes instead of a phosphor range, so some color rendering will be a bit off… while the eye will see the light as ‘white’ individual colors will reflect the three peaks a bit differently than a smooth spectrum, so some colors shift and the CRI Color Rendering Index goes a bit lower).

I’m one of those folks who can see flicker in lights at a little faster rate than most folks. In the old TV’s I could see some of the ‘squirm’ and from even 60 Hz tube (magnetic ballast) bulbs I notice the flicker. 50 Hz would drive me nuts… The Electronic Ballast with 10 kHz type ranges make the CFL useful in a lot of places where I just could not stand them before. Phosphor persistence matters… one of the minor problems with the LED RBG approach. No phosphor means no phosphor persistence means you flicker at the rate of the power supply to the LED. Don’t know what that will do at higher frequencies. BTW, different species have different max flicker rate perceptions, so what is OK to you may be a strobe light to your pets…

Had an old wooden cabinet radio with a giant speaker in it (tube driven…) that I just loved. Digital never could come close. Why? The cabinet was designed by folks who made musical instruments. Not a faithful reproduction of the signal, but with rich wood tones… Seemed to make everything sound better. Plastic never could come close.

Might be faster just to put a CFL or IC bulb in the bedroom and other ‘just prior to bed’ area and see what happens.

Oh Dear! Keep it away from the bread making and brewing areas!!

But it looks like maybe I can put them in the refrigerator to good effect!

Last time I was at a Home Depot they had Philips Incandescent bulbs in dozen packs for something like 19 cents / bulb ( Florida). It was abit under $3 IIRC. ( I have several in my stash…) It might be cheapest and easiest to just go buy a box and try them. Worst case, you have some “trade goods” for after the ban… ( I expect them to go for about $2 to $4 each to desperate folks who really want them…)

Oddly, recent advances in biology have indicated a closer relationship of fungi to animals than to plants… so you might be on to something there…

Part of why my lighting plan has an incandescent in almost every room with a CFL. Choice.

Exceptions are the kitchen (only one bulb – but an IC ‘night light’ plugged in), the Garage (temporary occupancy…), and the kids room (who wants to listen to Dad drone on about light bulbs…).

In the living room, the table lamps are ‘mixed’ and the pole lamp is too. So you can set the mood as comfortable OR make it ‘cleaning time bright’… Bedroom has 2 (IC on dimmers for longer life and more mood choices, HIgh Efficiency lighting for those cleaning and working moments… or as ‘nobody home’ fill lighting.

I can just FEEL when an fluorescent bulb is on. But the high frequency electronic ballasts have helped. Using them in mixed sets makes it “OK”, but not great. That was why I was converting to LEDs in selected fixtures. To deprecate the CFLs and replace some IC on dimmers (where I didn’t want the reddening of the light at low settings). Now that’s all out the window for a while as I do a bit of a re-think…

The Garage recently got new bulbs ( I had some old Circline 8 or 9 inch screw in ballast that had been left ’empty’ where their bulbs died a decade or so back – since the ‘new’ curly bulbs on subsidy where cheaper than the replacement bulbs. That have a nice plastic cover on them too. I decided to put them back in service in the garage just a month ago or so.) Looks nicer than the naked curly bulbs… ) so not a lot of need in the Garage…

Not sure what I’m going to do now in the ‘remix’…

New meaning to “blue screen blues”? -)

Spouse reports today was not as deep a sleep as the first night, but still better than prior times. I’m not all that surprise as a first ‘deep sleep’ after being sleep deprived is usually followed by a less deep one on the rebound.

That 𔄚 in a row” have been significantly (nearly dramatically) better is the start of a trend…

I think this issue “has legs”.

@ Power Grab “I sleep through the night when I take my dose of cod liver oil right before going to bed.”

Cod liver oil is the traditional source of D3. I have for the last few months been doing some home experiments with vitamin D3. I find that if I take about 8,000 or 10,000 units before going to bed, my dreams are more lucid, more coherent and more memorable. Note that there are mixed ideas on how high a dosage is toxic. Some sources say toxicity occurs with prolonged intake of 4,000 units a day, others say as much as 40,000 units or more. Anyway, point is, vitamin D3 seems, (at least to me) to influence sleep and dreaming. Experiment if you wish, but be aware that prolonged high dosages may be a problem.

On lights. I stick with halogen and triacs. I leave the damper coil out now that all modern equipment isn’t bothered by the feedback, so no audible noise.
You can adjust the color by taking 50 to 100 w lamps and turning them way down. Goes from a warm sunset glow all the way to bright white. I can’t think of a lightsource that is that versatile at that low cost at that long a lifetime. I had my first burnout only recently after 9 years of faithful service.

CFL makes my head spin, the new cfl’s run at 120 hz and give me nausea. And the awful colors, yuck. Makes everyone look like the living dead.

Good LED’s cost a fortune and aren’t half that long lasting as they claim. Affordable ones for sale here come from that famous place China, known for it’s barely substandard quality. They consume as much energy on as off.

@Jason Calley,
I don’t know how cod liver oil got into this thread but since you raise the subject here goes.

My mum (British for “mom”) used to dispense “Scott’s Cod Liver Oil” daily by the teaspoon. Of course I hated it and vowed never to touch that vile stuff once I broke free of her maternal influence.

Twenty years ago arthritis struck. I would have been forced to give up playing golf but for fish oil. Since then I have consumed a minimum of 4 grams per day. One benefit is that I can drive the ball 280 yards off the tee at age 75, much to the consternation of the old farts I play with. Unfortunately my short game sucks so my handicap is 21.

The Ott lamp comes awful close to the identified spectra – 435.8nm (ref.

wise/wise187/2004/reports/jasleen .) And my wife knits under one evenings…nights…into morning frequently. I don’t know if that is in the grey zone, but it’s worth experimenting on her.

Even further OT, i was given codliver oil in capsules which i always bit because i liked the taste so much.

Is anyone else getting the impression that the folks at UL aren’t doing as many tests, or taking all the time, as they should on all the new gizmo? This sounds like a job for our Super Heros: EPA Man, HHS Girl, CDC Woman, and DOE Boy! (Oh well, it might sell a few more comic books-)

PS: Think, maybe, the suicide rate isn’t all self-inflicted and there’s more murder than we realized in the National Stats?

So…..Blue light vs.codliver oil, why not Melatonin?

Well… we have a pattern / trend… MY English Mum fed Cod Liver Oil to me when I was ill and gave me cod liver pills as a vitamin ( and I liked the flavor of the pills rather a lot and bit them too –)

The UL just tests that things don’t start fires or electrocute you. (That is, the UNDERWRITERS of insurance policies are not taking too much risk…) So the UNDERWRITERS Lab tests for what insurance underwriters insure. They don’t insure quality of sleep…

The spouse took melatonin. Sometimes helped a bit, often not. The problem is that the body makes its own, and if you down regulate the normal level then add a bit, you still end up below desired levels. So you are in a race condition between the added in pills and the lowered by blue light. Better just to leave the race…

The main Sun´s wavelength is that which corresponds to the wavelength of Calcium (found in Sun´s chromosphere) so that cod liver oil (Vit D3) lacks its complement Calcium.
BTW, as our Sun is having troubles:
In WUWT article we find M.Vukcevic´s opinion:
Making reference to:
Many people is having troubles with orientation, equilibrium (dizziness). In special women. Why? because women have less hemoglobin, less iron than men (due to menstruation) and have no presence of magnetite in face bones.
…..interesting times, indeed!

Interesting link on that light. I love “kitchen science” and that looks like something you could do at home -)

Oh Dear! From that link, pretty strong stuff:

Over the past two years there have been a number of studies investigating the mechanisms
involved in the development of Age-related Macular Degeneration (AMD). The results of these
studies have consistently supported the premise that blue light exposure raises the level of
oxidative stress in retinal cells and promotes the development of AMD. The European Eye Study
(EUREYE) has now confirmed that blue light exposure combined with low levels of serum
antioxidants is associated with the formation of AMD.(1a)
The results of this new research on the pathogenesis of AMD provides compelling evidence that
increased exposure to blue light over a lifetime will advance the onset of AMD, and increase the
likelihood of blindness later in life. This has lead some prominent researchers on the
mechanisms involved in the development of AMD to now assert that “It is photo-oxidative
stress, or the cumulative exposure to free radicals from blue light over a lifetime that causes

That mouse study also would point toward avoiding blue CFL ( “Daylight” or 5000 K type) bulbs as well.

I have a DVD recorder in the bedroom that has a modestly bright BLUE running LED. I have to keep it powered off if I’m trying to sleep. Had always just thought it was too bright but now I’m thinking maybe there’s more to it…

I’ve changed my background wallpaper on the laptop to black, but it still has a couple of ‘blue/white’ status LEDs on the edges. (Disk activity, power on, network connected, and battery charged). Enough to be an annoyance in a dark room while someone else is trying to sleep.

I’m going to be shopping for more things with red and green LEDs for status lights and less blue…

Another interesting characteristic of blue light is that it has a high enough energy to knock electrons right out of your retina’s ball park. It can contribute to macular degeneration. It can cause some materials to fluoresce in the (lower) visible wavelengths.

@gallopingcamel says: 24 July 2012 at 3:55 am

Old farts? WHo do you play with? Centigenarians?

My clock has a blue light. LED I suppose. It’s VERY bright. Like a bright night light. However, I can read it at night. I can’t read a red clock. My eye doctor says it has to do with the wavelengths that my old eyes can see well. My wife sleeps right next to this clock. Hmmmmmmmmmmm. She is developing macular degeneration (thought probably age related), but still I think that we might look around for a new alarm clock. Maybe amber?

You can try using color filters on your existing LED lamps if you can tolerarte losing a fair amount of brightness. The old gaffer/lighting tech side of my brain informs me that Lee Filters now produces a line of filters especially for LEDs that might be helpful.

I haven’t used LED’s in that capcity since I am a bit of a neanderthal and am most familiar with tungsten, HDMI, and fluorescents, but you can give the folks at Lee a tootle, or call your nearest theatrical supply or rental house for more info.

Ah. even better, looking a little further down the page I see that Lee has a series of four LED conversion filters.
622 – converts white LED of 7000K to 3200K [tungsten]
624 – converts white LED of 6200K to 3200K [tungsten]
626 – converts white LED of 5550K to 3200K [tungsten]
628 – converts white LED of 5000K to 3200K [tungsten]

EM – “UNDERWRITERS Lab tests for what insurance underwriters insure. They don’t insure quality of sleep…”

Hummmmmm… bet the boys at UL will soon be worrying about the quality of sleep and retinas soon, something tells me a few thousand lawyers are taking depositions and drawing up formal complaints as we speak. Wonder how they found out?-)

Nowadays its fashion to put blue leds in just about everything. The first thing i always do is screw them open and replace the blue with another colour. For some reason blue leds really shine intens eand are very irritating. You just always see them. The other i bought an eight channel HDMI switcher. All blue indicators. Pity about the garantuee but that is just insufferable.

I am not a doctor, nor do I play one on TV… It is very possible that your spouse is reacting to some lighting issues. I have no way of knowing. But you indicated on a posting several months ago, IIRC, that you had children and friends of children in and out of your house. Then the other day, you said that your son had moved out of state to build a church. This comment is just from personal experience, but there might be some “empty nest” issues going on as well. I did the dance of joy when my daughter left for college several years ago, thinking that I was finally going to get some peace and quiet. It got too peaceful and too quiet in a big fat hurry. I found myself watching TV late into the night and not sleeping well when I finally did get to bed. It wasn’t what I would call depression, it was just a new stage in my life that took some getting used to.

I don’t know your wife’s situation, but it could be that there are several things going on at the same time that are making sleep difficult. Just a view from the feminine side.

@Judy F It is interesting a female´s point of view. Guess you are right.

The Son that went off to build a church did so from Los Angeles. He has been ‘out of the nest’ for 4 years of college and a couple of years of a job post college.

The “kids” coming and going are my Daughter who is 󈬄 something” and her friend. Been going on for a few years now about the same.

Reasonable things to highlight given the data you had available, but not things that have changed in the last few years (added data) so not likely issues. We’ve also gone through ‘end of school year’ and ‘summer off’ for a dozen years now without this happening.

That things improved a lot on changing the lights back gives a pretty good confirmation. (We need to do a swap to LED again trial to confirm, but right now SWIMBO is not interested in my experiments -)

Also a good idea… but a filter and housing is likely to cost more than the bulb ( $10 ). I’m happy just to put in a different bulb from my inventory (as I have a lot right now) and hopefully over time the LED makers will realize this is an issue and “fix” it. ( i.e. maybe I can toss $15 – $20 / bulb at new LED bulbs that are not ‘blue rich’… while these bulbs either stay in inventory or go to “blue OK” uses. Yard lights after the bunnies are gone ( not planning to raise bunnies for the next 20 years too -) or garage lights or porch light or…

Yes, I have a decade scale time granularity to my lighting inventory -) (Forced into it by the Bulb Ban, but “It is what it is. -Paul The Czech / Swiss Mechanic”.)

I’m happy with a white faced unlit clock and a bedside light… but what do I know -)

I think there are also GREEN glowing clocks out there too. Typically green-yellow is the color more readily seen by folks.

BTW, on the Macular Degeneration: Found several pages saying UV and Blue light cause and / or aggravate it. One recommends glasses with a specific filtering in them. IIRC it was a specific cut off at 400 nm. It does look like cutting out blue light makes a difference in prognosis.

Researchers have identified melanin as the substance in the skin, hair and eyes that absorbs harmful UV and blue light. It is the body’s natural sunscreen protection. Higher amounts of melanin afford greater protection against damaging light rays, but melanin is lost as we age. By age 65, about half of the protection is gone so that we are more susceptible to eye disease such as macular degeneration. The Schepens Eye Institute reports that “the blue rays of the spectrum seem to accelerate AMD more than other rays of the spectrum.” Very bright lights such as sunlight or its reflection in the ocean or desert may worsen macular degeneration. The Institute recommends that sunglasses protect against both blue/violet and UV light.
Misleading claims about certain glasses providing UV protection can be easily confusing to consumers. A pair of glasses might be labeled UV-absorbent, for example, but the label might not indicate exactly how much UVA and UVB rays are blocked. Sunglasses should be labeled UV 400. It is recommended that you protect yourself from UV radiation up to 400 nanometers, which extends into part of the visible spectrum to ensure complete blockage of ultraviolet light. This is what distinguishes “cheap” sunglasses from more expensive ones.(1.)

So looks to me like folks with Macular Degeneration need to be looking at the world through rose colored glasses -)

These folks are a bit more ambiguous (but also fail to mention sun sensitizing drugs like tetracycline as potential enhancers of sun damage to eyes):

In many primate studies, blue light has been shown to cause a photochemical reaction that produces free radicals in the RPE and the rods and cones. Researchers believe that these free radicals interact with the high oxygen and lipid content in human rod and cone tips to produce abnormal chunks of metabolized waste that cannot be properly processed by the RPE, clogging up the macula’s maintenance system and producing dry macular degeneration.

Melanin, the substance that gives eyes their color, protects the macula by trapping light rays so they don’t reach the macula and cause damage. People with fair skin and blue or light-colored eyes may be particularly susceptible to macular damage by blue light because they have less melanin in their irises. Their blue eyes transmit up to one hundred times as much light to the back of the eye as dark colored eyes do. Additionally, when the light reaches the choroid and RPE of people with fair skin and blue eyes, there is less melanin there to absorb the radiant energy, leaving these tissues more vulnerable to light damage. Can blue light rays cause macular degeneration? Can you reduce your risk by protecting your eyes from blue light? The answer is maybe.

Although the laboratory studies on animals seem nearly unanimous, the real world studies on people have produced conflicting results. Some studies positively link macular degeneration with any kind of light exposure, other studies have found a weak correlation between macular degeneration and blue light exposure, and yet a third group of studies has found no correlation at all between macular degeneration and sunlight. One Australian study concluded that the problem is not total sun exposure, but exactly how sensitive you are to the sun. It hypothesized that people who have plenty of melanin and don’t tend to burn easily are at less risk for macular degeneration than people who burn easily or are bothered by by sun glare. This study also concluded that people with blue irises are at increased risk for ARMD. These results, which have not been replicated or confirmed, do not allow me to state absolutely that blue light contributes to the development of macular degeneration, but it is certainly plausible. Based on the possible benefit, I recommend wearing blue blockers, especially if you have fair skin and blue or light-colored eyes, if you have any other risk factors, or if you spend lots of time in bright sunlight, or on water, sand, or snow, which reflects sunlight. Alternatively, wear a sun visor when you are outside.
Blue Light and Blue Blockers

Unlike UV light, blue light is visible to us. Blue light waves are what makes the sky, or any object, appear blue. Blue light waves are also very short and scatter easily, so a great deal of the glare we experience from sunlight also comes from blue light. Since we can’t see UV light, we also can’t see the lens filter used to protect us from UV rays. Conversely, since we can see blue light, we can also see blue blockers, the lens filters that block blue rays. Blue blockers do not act like regular sunglasses. They appear tinted, but they do not reduce overall light or make the world look darker. They alter the appearance of blue and green colors and reduce glare, but they don’t affect the way other colors appear. In fact, they may even improve color contrast. Because of these characteristics, blue blockers were very popular a few years ago as sports glasses. Many people with macular degeneration find them particularly helpful regardless of their health benefits, because they reduce glare indoors and outdoors while keeping the world bright and visible.

At any rate, as I already hide from the sun a lot of the time I’m not too worried about my blue eyes or redhead gene impact on the eyes… but I might start wearing cool shades anyway -)

This link explores “light therapy” for S.A.D. using a similar blue peak ‘light box’ instead of a full on UV lamp and finds it effective but then also explores the issue of light and other problems as well. It may be that we just need to use the LED bulbs in the first half of the day (so the biological clock stays right and the S.A.D. gets a treatment…) while swapping to yellower later in the day. (Which would be nice and would let us dump the UV 20 minute morning treatments…)

Golly, that light stuff is complicated… Maybe I’ll just put in some large sky lights and be done with it -)

After the DVD writer experience, I now look at anything going into the house and if it has bright blue LED status lights on it, don’t buy it. Sadly, my Mercedes has a bright blue High Beam notification light (which seems really dumb to me… just when you need to see in the dark the most, dump a color of light at your eyes that cuts down on night vision…) but I just put black tape over it for long drives (and don’t use high beams most of the time…)

Danger No. 2: LED Light Exacerbates Chronic Disease Through Mitochondrial Dysfunction and Suppressed Energy Production

Importantly, LED light affects your mitochondrial function and may exacerbate health problems rooted in mitochondrial dysfunction , including metabolic disorder and cancer.

Chromophores are molecules that absorb light. There's an optical tissue window ranging from 600 to 1,400 nanometers, which means it is almost completely covered by the near-infrared- part of the light spectrum. This optical tissue window allows the radiation to penetrate an inch or more into bodily tissues.

Chromophores are found in your mitochondria and in activated water molecules. In your mitochondria, there's also a specific molecule called cytochrome c oxidase that is involved in the energy production within the mitochondria. Adenosine triphosphate (ATP) — cellular energy — is the end product.

ATP is the fuel your cells need for all of their varied functions, including ion transport, synthesizing and metabolism. Your body produces your body weight in ATP every day. And, while you can survive for several minutes without oxygen, were all ATP production to suddenly stop, you'd die within 15 seconds. This is why lighting is so important.

Light is a sorely misunderstood and overlooked part of the equation for biological energy production, specifically at the mitochondrial ATP level. Since the cytochrome c oxidase is responsible for an increased production of ATP, the cell has a better supply of energy, which allows it to perform better, and this is true no matter where the cell resides.

Don't Fear Coffee. Coffee has been unfairly demonized. The truth is that it's actually very healthy. Coffee is high in antioxidants, and studies show that coffee drinkers live longer, and have a reduced risk of type 2 diabetes, Parkinson's disease, Alzheimer's and numerous other diseases. Eat Fatty Fish. Pretty much everyone agrees that fish is healthy. This is particularly true of fatty fish, like salmon, which is loaded with omega-3 fatty acids and various other nutrients. Studies show that people who eat the most fish have a lower risk of all sorts of diseases, including heart disease, dementia and depression.

This means liver cells with more ATP will be able to detoxify your body more efficiently fibroblasts in your skin will be able to synthesize more collagen fibers and so on, because ATP is crucial for all cellular functions.

The key take-home message here is that your body's energy production involves not just food intake. You also need exposure to certain wavelengths of light in order for your metabolism to function optimally. This is yet another reason why sun exposure is so vitally important for optimal health, and why LED light bulbs are best avoided.

Screen Time recommendation to Protect your Children’s eyes

The eyes of growing children are very sensitive to light as well as changes in the surrounding environment. This is especially true when it comes to the use of screens either for academics or for pleasure. Managing the screen time of your kids is very important if you wish to protect their vision when it is most vulnerable due to their age. Here are some ways to regulate screen time so as to protect their eyes.

Teach them good Screen habits

The best way to protect them is to cultivate them with good screen habits from an early age. Children pick up things faster than adults and are known to run with whatever they learn all the way into adult life. Adopting helpful tips will protect them both now, and in the future, so they will be less likely to suffer from dry eyes or eye strain. Here are some tips to imbibe.

  • Use the 20/20/20 rule: Encourage them to look at least 20ft away from the screen every 20 minutes for 20 seconds.
  • Set a timer: To help them master the 20/20/20 rule, consider setting a timer to remind them when it’s time to look away.
  • Mark them read actual books sometimes: Ebooks convey as much information as actual books, but reading actual books helps them avoid the challenges of viewing a lighted screen for a long time. Even when they read actual books, encourage them to observe the 20/20/20 rule often.
  • Discourage screen usage outdoors or in brightly lit rooms: The glare from a screen when viewed in a lighted space can strain the retina considerably. Discourage the use of phones, tablets, or computers outside or in brightly lighted rooms.
  • Adjust screen brightness and contrast: Before your child starts using a device, make sure you adjust the screen brightness and contrast to suit their eyes. The screen should not be too bright or too dim. This is very important if the device does not belong to them. If it is theirs, you can set the brightness to a default setting for safety.
  • Teach proper sitting posture: A poor posture can lead to eye muscle tightness and migraines. Teach them how to sit properly when using a device.
  • Hold the device farther away: Holding the device too close to their eyes is not ideal. Encourage them to hold it at least 18-24 inches away from their face.
  • Remind them to blink: Regular blinking is necessary for the eye to retain moisture. Failure to blink regularly leads to eye dryness and blurry vision.
  • Encourage outdoor play: Sitting in front of the screen all day is not ideal for your child’s health. Encourage them to play outdoor and to engage in physical activities like sport.

Before you place an order for an LED screen or bulb products, make sure you are getting a product of only the best quality. Take your time to read product reviews posted by previous buyers. Also, check for the track record of the manufacturer to see how good their products are. Some manufacturers are known to sell bulbs with a warranty of 3 years or more attached to their products. Buying warranty backed products will help you save money.