“A good laugh and a long sleep are the best cures in the doctor’s book.” – Irish Proverb
The evidence for the health benefits of adequate, restful sleep is overwhelming. Decades of research has shown that sleeping between 7 and 9 hours per night can relieve stress, reduce the risk of many chronic diseases, improve memory and cognitive function, and may even help with weight loss. (1) As many of us know by now, getting adequate, high-quality sleep is one of the most important, yet under-appreciated steps you can take to improve your overall health and well-being.
Yet for all we know about the benefits of sleep, there are millions of Americans who are still suffering from disordered sleep and insomnia. More than one-third of Americans report getting less than 7 hours of sleep per night, and 63 percent of Americans say their sleep needs are not being met during the week. (2, 3) The negative effects of sleep deprivation are serious: sleep durations that are consistently shorter than 7 hours in a 24-hour period are associated with cardiovascular disease and diabetes risk factors, depression, automobile and workplace accidents, learning and memory problems, and an overall increase in mortality. (4) Some may argue that poor sleep can even undo the benefits of a healthy diet and exercise routine. (5, 6)
Could using electronics at night ruin your sleep and increase your risk of death and disease?#chriskresser #healthylifestyle #artificiallight #bluelight
So what’s causing this epidemic of sleep disruption in our country? Many experts feel that our excessive use of communications technology (e.g. cell phones, laptops, television, etc.) is driving this significant level of sleep deprivation. If this is the case, it’s no wonder so many Americans struggle with poor sleep, since 95 percent have reported using some type of electronics at least a few nights a week within the hour before bed. (7) Checking email, watching your favorite late-night comedian, or responding to a text message in bed seems harmless enough, but the sleep disruption caused by these light-emitting devices is significant and potentially harmful to your health.
Research has demonstrated that nighttime light exposure suppresses the production of melatonin, the major hormone secreted by the pineal gland that controls sleep and wake cycles. (8) Therefore, a reduction in melatonin at night is associated with subjective levels of sleeplessness. (9, 10) But melatonin suppression has far worse consequences than simply poor sleep outcomes: it has also been shown to increase the risk of cancer, impair immune system function, and possibly lead to cardiometabolic consequences such as type 2 diabetes, metabolic syndrome, obesity, and heart disease. (11, 12, 13)
Blue Light and Melatonin Suppression
It is well established that short-wavelength or “blue” light is the most melatonin-suppressive; this is the type of light typically emitted by devices such as televisions, computer screens, and cellphones. (14, 15) To produce white light, these electronic devices must emit light at short wavelengths, close to the peak sensitivity of melatonin suppression. (16) This means that products such as tablets, smartphones, and other devices with self-luminous electronic displays are major sources for suppressing melatonin at night, thereby reducing sleep duration and disrupting sleep. (Figure credit: Wood et al, 2013)
Along with blue light emitted from electronic devices, research has shown that being exposed to normal levels of room lighting can have similar negative effects on melatonin. One study showed that one hour of moderately bright light exposure (1000 lux) was sufficient to suppress nocturnal melatonin to daytime levels. (17) Since melatonin suppression is intensity dependent, researchers suggest that lower intensities can have similar suppression effects at longer durations; for example, two hours at 500 lux would have a similar effect as one hour at 1000 lux. (For examples of lux values, check out this helpful chart.) This means that typical room light alone can have a similar suppressing effect on melatonin secretion as the light from backlit screens. (18)
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How to Prevent Melatonin Disruption (Without Tossing Your iPhone)
There are a few possible solutions for reducing your exposure to blue light at night. One that is commonly used in the ancestral health community is f.lux, a program that makes the color of your computer’s display adapt to the time of day, warm at night and like sunlight during the day. This program can be installed on computers, iPads, and iPhones, and may have a significant effect on your melatonin secretion when using these devices at night. The best part about this program is that it turns on automatically in response to the daylight in your particular time zone, so there’s no need to remember any adjustments to the screen.
A better option, in my opinion, is to use amber-lensed goggles once the sun has gone down. These blue-blocking lenses are highly effective in reducing the effects of blue light exposure, and in most cases completely eliminate the short-wavelength radiation necessary for nocturnal melatonin suppression. (22, 23, 24) These goggles have been shown to improve sleep quality as well as mood, simply by blocking blue light and simulating physiologic darkness.
The main reason I recommend using these goggles is because normal room light alone is enough to suppress melatonin at night, and unless you’re shutting off all the lights in your house when the sun sets, you’re still at risk for disrupting your melatonin-driven circadian rhythms. (25) While f.lux is a useful tool for your backlit devices, it’s nearly impossible to address all sources of melatonin-suppressing light in today’s world of modern technology and late-night work and entertainment habits. Amber-colored goggles are one of the only tools available to completely eliminate all blue light exposure at night, without ‘going off the grid’ and powering down your entire house after 7 PM.
There are two excellent (and cheap!) options for amber-lensed goggles on Amazon. The cheapest and most popular option is the Uvex brand, but if you wear eyeglasses you’ll need to get a wraparound pair like the Solar Shield brand. I’ve had many patients swear by these goggles, and if you can get over the dorkiness factor, you may find they make a big difference in your sleep quality, and perhaps even your general health and wellbeing as well!
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Thanks so much for this article. Will be trying the glasses/goggles and f-lux. Need to find some way to cause better sleep as the “waking up” during night due to cortisol/adrenals/Hashimoto’s is obviously impacting my waking moments. Thank you once again for providing very useful information.
Hi. Wraparounds over glasses are ok at home, but are there prescription amber wraparound glasses to wear out of the house at night?
My optometrist said they they can get “Cocoon” prescription wraparound product, and they have a catalog. Anyone know about those?
He mentioned something about polarization in addition to the amber. Would polarization be good, bad or indifferent?
Also, there seem to be loads of Solar Shield clip-ons on ebay. Would those help even though they’re not wrap-around?
Thanks
Russ
I hate to sound stupid, but why wouldn’t taking a melatonin pill solve ther problem?
Oral melatonin dosing can be highly variable from one person to the next and the timing of the dose is crucial as taking it at the wrong time can reset the internal clock and promote insomnia when you want to sleep.
The glasses are just a return to pre-electric lighting as far as the body is concerned. Far safer and cheaper.
this is good articles. when i was a kid, i don’t know why do i have to turn off the lights at night even my laptop. the explanation is easy to understand. thank you
A great app for reducing the temperature of the screen without simply dimming it, and it is automated by time, etc.
Twilight (android)
https://play.google.com/store/apps/details?id=com.urbandroid.lux&hl=en
For anyone who is interested, I bought the expensive amber glasses available from lowbluelights.com and they do appear to block more blue light than the Uvex $8 glasses. The more expensive lens is clearer and of a higher quality.
I think the Uvex glasses are perfectly fine (they do block most of the blue light), but I can definitely say that the lowbluelights glasses block even more blue light. The company also offers a 30-day money back guarantee.
Thanks Dan for the reassurance – I just bought the $70 Low Blue Light glasses and was wondering if I should have gotten the the $10 Uvex glasses instead.
Hi Chris,
Another fantastic article.
Quick question: Does these glasses also inhibit the blue light emission?
“Uvex 9176-020 x-act Amber safety specs with amber lens”
I first read about the following from the book ‘Lights Out’ by T.S. Wiley and Bent Formby, Ph. D., then Googled it:
“The circadian clock times a wide range of behavioral and bodily functions by controlling temperature and the release of hormones. And until now it has been widely believed that it is set by daily and seasonal changes in the light that enters through the eyes.
“But our results challenge this belief. The study demonstrates that circadian rhythms in humans can be altered simply by shining light on the backs of people’s knees,” says Dr. Scott Campbell, director of the Laboratory of Human Chronobiology at Cornell University Medical College in White Plains, New York.
Writing in the journal Science, Campbell and colleague Dr. Patricia Murphy describe an experiment in which volunteers agreed to spend four days at their laboratory in a dimly lit suite. Periodically, they sat in a reclining chair while the backs of their knees were exposed to bright light delivered through a fiber-optic pad in a housing strapped to their legs. The pad was adapted from those used to treat infants born with neonatal jaundice. None of the volunteers knew exactly when the light source was switched on.
The knee was chosen as the site of the experiment because it was far from the eye, therefore minimizing any risk that light shown would enter the subject’s eye.
The researchers noted that the light exposure on the back of the knee was associated with shifts in the timing of body temperature changes and in the release of the hormone melatonin from the pineal gland, located deep in the brain. ”
Makes me wonder if the glasses are enough to make a difference then, if what they found above is true, that the skin is also light sensitive?
The Campbell and Murphy study you are referring to has never been reproduced — and many researchers have tried. For instance, here is a study that was unable to reproduce Campbell and Murphy’s results:
Failure of Extraocular Light To Facilitate Circadian Rhythm Reentrainment In Humans: 2000, Vol. 17, No. 6 , Pages 807-826 — Charmane I. Eastman, Stacia K. Martin and Marc Hebert
Biological Rhythms Research Laboratory, Rush-Presbyterian St. Luke’s Medical Center, Chicago, Illinois, U.S.A.
And here is a study that shows that light on skin does not affect melatonin:
Bright light exposure of a large skin area does not affect melatonin or bilirubin levels in humans: N Lindblom, T Hätönen, M Laakso, A Alila-Johansson, M Laipio, U Turpeinen — Pediatric Neurology, Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland.
Biological Psychiatry (impact factor: 8.28). 01/2001; 48(11):1098-104. pp.1098-104
Source: PubMed
The Campbell and Murphy study was likely flawed as nobody has ever been able to reproduce it and the evidence against it is far greater than the evidence to support it.
You would think that the results would be easily reproducible if they were true — or relevant. Even if there was some merit to Campbell and Murphy’s findings, it would likely have little value, since nobody sleeps with a BiliBlanket strapped to their knees. 🙂
Hi Roy,
The “Light behind the Knee” study has been refuted. Indeed, the photosensitive ganglionic cell layer of the retina is solely responsible for setting the circadian because it contains melanopsin which is able to respond to light independently from the rods and cones. Wearing a sleeping mask is enough to replicate darkness & trigger melatonin in most people; the glasses by low-blue-lights are effective when used properly. In 1923, a Harvard grad student was the first to suspect there was another photoreceptor besides the rod & cones. Nearly 80 years later, Oxford’s Dr Russell Foster was the first to prove him right, followed in new detail by several other researchers including Drs Richard Stevens, Steven Lockley, David Blask and George Brainard. Here is a link to a phenomenal lecture that you can find on youtube in 3 parts by Russell Foster called “Pillow Talk- The Biology of Sleep “. See Part 1 at 31min50 sec to listen to Dr Foster’s amusing comments about the “Light Behind the Knee” paper including “There was a lot of bloody nonsense about shining night light behind the knee, could shift the body clock… Oh, it was just awful… this wretched paper, Light Behind the Knee came out in science….” https://www.youtube.com/watch?v=nttBRp_VlZM I find the health consequences of circadian & melatonin disruption by artificial light at night fascinating and essential to get out to the entire world’s population. This single act will reduce suffering by millions, if not billions, of people. Society has unwittingly turned night into day. This can have as much impact as lead poisoning – which brought down the Roman Empire… only worse, because it affects nearly all of nature as well.
I do a lot of late night design work on the computer and find that ever since I used f.lux I definitely sleep better. I need my room to be dark when I sleep so I dimmed and blacked out my cable box and router lights with Dimmys which work wonderfully.
I started wearing blue blocking glasses a few months ago and it did the trick for my insomnia. I immediately had trouble sleeping after installing energy saving LED lights around the house. The blue blocks made all the difference. At first I used a pair of darkened blue block sunglasses I happened to already have. I’ve since bought the pair Chris recommends on Amazon and they’re great. …A very economical solution to my sleepless nights.
Hi!,
I have what you call Insomnia quite frequently and so I ‘ve discovered that Polaroid Sunglasses are ideal for my sleep at night. I’m not sayimg this will work for everyone but, It’s a real good way of limiting the light in your bedroom at night. Put your sunglasses on 1 hour before going to bed.
Thanks for reading about my idea, hope this helps.
Check out this great book by T. S. Wiley “Lights Out” she goes into great depth about the importance of sleep, and the how and why lack of sleep (especially in complete darkness) can be detrimental to your health.
Hi Teresa,
Look at my comment above. I mentioned the same book. Quite the ‘lifestyle’ change!
I know I’m very sensitive to light – I get headaches & sore eyes if I sit in artificial light in the daytime, & I’ve gone to some trouble to make sure I get natural daylight or blue light… I’ve been aware of the desirability of darkness at night for sleep, & have used f.lux on my computer for some time now, as well as using only a flashlight if I get up in the night. But I didn’t know about the amber goggles -I’ll definitely check them out. Maybe it will help me sleep through the night properly.
When I feel sleepy, I get ready for bed (turn of lights, clean teeth etc). By the time I’m in bed I’m wide awake – very alert. I then can’t sleep for hours, and my room is very dark. Even if I keep the yellow tinted glasses on the whole time, it makes no difference. I wondered weather the walking around getting ready for bed, maybe even using the noisy electric touchbrush, is giving off other hormones telling me to wake up… As an experiment, one night I just went straight to bed without “getting ready for bed”, not even changing my clothes, and I found that I fell asleep really quickly. Maybe light is just one part of the puzzle…
Electric toothbrushes reportedly radiate huge amounts of EMF’s to the brain. This artificial energy may stimulate some area of your brain, which then contributes to keeping you awake?
“Electric toothbrushes reportedly radiate huge amounts of EMF’s to the brain” no there is not radiat any huge amount of emf dont spread myth,
“. This artificial energy may stimulate some area of your brain, which then contributes to keeping you awake?” there was some studies showing that emf can lower melatonin lvl but many more with better methodology dont find such assocation.
Thanks Dan & Audrey 🙂 I think I will give the screen filter a try! I am curious to test this for a period of time – I have always wondered why I have problems falling asleep and often wake up feeling beat up – I eat pretty healthy, exercise, meditate and have very little daily stress – so I’m thinking maybe this will have an effect – and if it doesn’t I guess tried most anyway:)
Low-blue lighting/filters are a great start for encouraging melatonin production and stopping evening cortisol. And you may notice that playing with low-blue lighting alone is all you need to reset your body.
However, if you find that low-blue lighting isn’t enough to get your evening cortisol down you should consider trying HeartMath® (specifically their “Heart Lock” technique with any of their heart monitoring devices) while listening to relaxing music right before bed. After a few weeks of that pre-bedtime routine, your evening cortisol should normalize, if you are generally healthy. I believe Kresser recommends the “Rest Assured” sleep CDs — which is another natural approach to reducing evening cortisol. Good luck!
Hi Nik, There is nothing you can do at night via computer settings or software that will eliminate enough of the blue wavelengths emitted from your computer monitor and still allow the user a maximum natural melatonin production. Using a filter over your screen (assuming an especially dark room) or wearing the glasses that filter out all the blue are the best options other than NOT using the computer at night. Personally, I am trying my best to reduce computer use at night, and starting my day earlier. In the morning, the blue light emitted from the computer is actually an advantage, and helps wake me up!
Thanks Dan! Nice that it can go down to 2300K on the Mac.. That would be ok I guess.. And then no lightbulbs… Does anybody know another program that can go that low on a PC?
I have a pair of glasses but they are just too annoying for me. So I would rather make my surrounding light dimmed. On my monitor I can go into the settings and adjust red/green/blue – I guess I could just turn the blue all the way down??
Audrey is correct. There is really nothing you can do to any monitor to get it below 2000ºK. Keep in mind that the morning is sunrise is around 2000ºK, so you really need to be warmer than 2000ºK to encourage melatonin production
If you think about it, we evolved to wake at sunrise (i.e. when light becomes cooler than 2000ºK) — which causes our bodies to suppress melatonin and increase cortisol as part of our circadian rhythm. So, sitting in a dark room with a 2300ºK monitor won’t do you very much good in the long run — it would be like trying to get ready for sleep while staring at an early morning/dawn sun. It’s certainly better than sitting in a room with 3600ºK lamps, but your melatonin will still be suppressed.
If you don’t like the glasses, your best bet are the low-blue monitor filters from lowbluelights.com. Not much more you can do beyond that.
I have f.lux on my computer – but the lowest setting 3400K – isn’t that still too high?? Wouldn’t around 2000K be better?? Is there a program out there which can go lower? Or would manually lowering the blue light on your monitor be the solution?
f.lux on the Mac can get down to 2300ºK. They call it “candle” setting, but in reality a candle is actually around 1800ºK. Anything below 2000ºK would be ideal — but f.lux cannot make your monitor that warm.
f.lux is really intended to mimic your ambient light, whatever that may be (halogen, tungsten, etc). The idea is to have your monitor mimic the effect of reading a book under your lights. Keep in mind that even if your monitor were 1800ºK and your lights were 3600ºK, your melatonin will still be suppressed by the 3600ºK lightbulbs.
In any case, lowbluelights.com sells plastic monitor filters that will filter out all blue wavelengths. You just press them down on top of your iPad, iPhone or computer monitor. They even sell them for your TV.
However, in my opinion, nothing beats the glasses — since they filter out all blue light for you.
In your article, the word “f.lux” was a link to this website
https://stereopsis.com/flux/ where you can download the program
for free. I wanted to check in first and make sure this is the legit
website for that download. Would you please provide some links
that you know are safe? Thank you.
I bought this motion sensor night light at Walmart after reading Lights Out: Sugar, Sleep and Survival by Wiley several months ago. — https://www.amazon.com/GE-50723-Motion-Sensing-Auto-On-Nightlight/dp/B00032ATWO/ref=sr_1_1?ie=UTF8&qid=1365309047&sr=8-1&keywords=motion+sensor+night+light — The light is a dim white light, but my room remains dark until I wave my hand and the light goes on in the bathroom for me to take a bio-break. Wiley seems to have some controversy because of her interview with Lynn Sherr on ABC, but her book seemed to make sense. She said taking melatonin shrinks the pineal gland. I believe Robb Wolf recommended sleeping at a temperature no higher than 70 degrees. I like to use the sleep/eye mask that is contoured so the fabric doesn’t touch my eyes; it feels kind of spongey and I found them at TJ Max, but looks similar to this one on Amazon without the nose piece — (https://www.amazon.com/Dream-Essentials-Dreams-Contoured-Earplugs/dp/B000CCI4YU/ref=sr_1_cc_2?s=aps&ie=UTF8&qid=1365310129&sr=1-2-catcorr&keywords=eye+sleep+mask) — I also covered the light on my smoke alarm with several layers of blue paint tape (so it doesn’t get tacky) and I bought a spring rod shower curtain (inexpensive at Big Lots) to place black out curtains (from Bed, Bath and Beyond) in my window as I have a vertical window treatment outside the window opening. My TV has to be shut completely down at the surge protector because of the red sensor light and it is behind armoire doors. Additionally, I started wearing ear plugs so I can listen to my breathing to try to shut off my brain (mostly singing songs, not stressful stuff). Like J.W. Simpkins comment above, I am starting the epsom salt baths too (inexpensive at Big Lots). By the way, his suggestion on the cat suit gave me a belly laugh. Besides the sexy ones, there were some that looked like the men from the Big Bang Theory sitcom show would wear. With tv showing most of the shows on the computer including the news, I don’t have to put my tv on at night; I just watch them during the early evening or on the weekends.Thanx for the discussion and other book recommendations. I am ordering the Uvex goggles for not only me, but my children who are not sleeping well. My college child is overwhelmed with homework and stays on the computer until late.