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How Artificial Light Is Wrecking Your Sleep, and What to Do About It


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blue light and sleep, blue light melatonin
Blue light exposure at night can adversely affect a good night's sleep. istock.com/IngaNielsen

“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)

With serious consequences like these, preventing melatonin suppression should be a top priority in anyone’s healthy lifestyle.

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)

Melatonin graph

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)

Since it is predominantly the blue wavelength that is most affective in melatonin suppression, it stands to reason that blocking this wavelength of light should be enough to significantly reduce, or even eliminate the melatonin-suppressing effects of nighttime light exposure. (19) In fact, blocking blue light has been shown in several studies to be extremely effective in reducing the melatonin-suppressing effects of intense and/or blue light. (20, 21)

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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Join the conversation

  1. Our city has installed LED streetlights and in my neighborhood, my house on the corner has three lights very close. On some nights when it is cloudy or a new moon, I will wake up in the middle of the night and it feels like daylight in my room, hallway, living room and kitchen. I wonder if there are shades that a specific to blue light? Aside from wanting to make the case to the council, that would be my next best solutiuon.

    • Erin, that would be a great idea for window coverings and I hope you find some. That said, I know from experience that if you don’t cover your windows (at least your bedroom window) thoroughly, the light that gets in the cracks at the side seem like laser beams. 😉 I spent so much time trying to find a light proof solution for the bedroom window until I simply decided to cover it completely. My sleep has improved by leaps and bounds, especially as I only use my room for sleep; no reading and definitely no t.v. or phones. P.S. I bought some red blue-blockers from somnilight and they work much better than my amber blue blockers for t.v at night. Often I’ll also put them on to go to the bathroom in the middle of the night so that I can fall asleep again much faster.

  2. Since we are finding out that our bodies are far more whole and not segmented into different parts than we realized in times past, is the blue light issue also pertinent to our skin absorbing this? I’m wondering because I bought the blue-blocker glasses to wear in the evenings but the change is minimal.
    I have insomnia so end up falling asleep with a DVD on which goes to blue screen because the movie ends. I even sleep with the blue-blocker glasses on so that the TV light won’t affect me and for trips to the bathroom in the middle of the night.
    If skin can absorb this blue light then those of us who share my situation have further issues if we aren’t sleeping in black-out rooms. Yes, I’ve tried turning off the TV for several months at a time and insomnia got much worse. Can’t turn off mind!
    Can’t find any articles addressing the skin absorbing light question. Our skin absorbs a lot of things, maybe even this blue light. Anyone know about this?

    • Nancy, I just asked that very question yesterday on another site. It does emit the blue light, but some ppl will say that it’s not pointed directly at your eyes, so it’s not as bad. Apparently, the original Kindle e-ink didn’t have a light source, but not 100% sure. All I know is that when I read that they still emit blue light, I couldn’t personally take a chance. You can lower the light, though, so if you’re eyes aren’t as sensitive to light as mine, you may be able to get away with wearing blue blocker glasses while reading..

  3. Dear Chris,
    I am thinking that it would be good for us to use blue light at morning time. When we pass midday orange light could progressively added at evening time.

    What is your opinion?

  4. Hey Chris,

    Awesome post! I’ve been using f.lux for awhile but I feel like now I’m almost immune to it – is that a possibility or am I just being dramatic? I also use the function on the iphone to make it a bit darker @ night which helps when I’m in the bed and still want to read an article (like yours…haha).

    • I don’t think you’re being dramatic; I’ve found that I can’t read on my pc or phone after dark no matter what. I have f.lux on the lowest setting (1200 incandescent), plus I wear blue blockers and I find it far too bright. I did find their ‘darkroom’ feature and that’s a lot better, but within a short time, it also becomes too bright–my eyes adjust, I guess, and it becomes intolerable.

  5. Chris, I use the f.lux app on all of my devices and its helped a ton! I feel like the next step I need to take is to turn off all of the other artificial light that is in my house that keeps me feeling like its daylight when in reality its night time. I’m going to start my nighttime yoga practice with the lights off using f.lux and see if that allows me to more easily get to sleep.

  6. This is a really interesting article. I want to say that i bought my blue light blocking glasses on http://www.thefreeglasses.com
    I just received it today that’s why i’m talking about it. It look like normal glasses not like orange ugly glasses on the internet.

    • thanks for the link, i just received my prescription + blue light blocker glasses!

  7. Chris, this is an important post, and perhaps the most well-informed comments section I’ve seen! I too, use f.lux (and Twilight on android) every night, and it certainly makes a huge difference. Even so, I’ve found that the best thing at night is using native amber LEDs, which emit essentially no blue or green wavelengths to begin with (single color LEDs, like lasers, emit only a very narrow band of amber light).

    After my favorite amber book light broke (and went entirely out of production), I actually started a whole company to start producing amber book lights myself. That’s dedication to an accessory. Anyway, though you might be interested in an amber desk lamp or book lamp, which are available here: http://www.SomniLight.com. I find it’s more comfortable than wearing blue-blocking glasses at night.

    Under “Research” I’ve also collected all of the latest research on blue light, melatonin production, and health. It’s some fascinating stuff! Anyway, thought you might find it interesting!


    • I just ordered from your page last week (the amber desk lamp for reading and the red blue blockers) and am anxious to start using them. Funny thing is, I didn’t make the connection between your post here and finding the somnilight site when I searched for ‘red blue-blockers’. Small world…

  8. Two questions

    1. I use amber Uvex goggles. I don’t go to sleep until ~midnight, which is 6 hours after the sun sets. Should I wear orange goggles for the entire 6 hours (currently, I wear them for 2 hours before)

    2. Using goggles with lights/electronic devices is better than not, but is avoiding lights all together the best option? (i.e., blocking blue light is good, but blocking all light is better)?

  9. Can f.lux be updloaded/downloaded onto a new 2015 LED Smart TV?? Ever since we purchased our TV, my husband and I both notice a decrease in sleep and it is driving us crazy!

    • Hey Jennifer,

      I have an Samsung LED Smart TV, and it’s possible to change the color on it to red. I went to the advanced settings and did this. This basically does what f.lux does.

      I’d also recommend wearing the blue light glasses Chris Kresser recommends and switching to red or amber lightbulbs. I tried both of the glasses recommended on this site and I liked the Uvex pair better; it’s very hard to see with the other pair on.

  10. I would definitely recommend downloading f.lux. It’s free, it took my computer less than 30 seconds to download, and it’s worked wonders for my insomnia I was suffering from for a while. I like to watch Netflix to help me sleep at night, and with no blue light, I still feel tired, as opposed to feeling more awake, and having eye strain like before. A+ for f.lux!

  11. Hi, all. I work under the usual ugly florescent lights in my office. I can see windows in the distance but not much natural light hits me during the day. Would appreciate any recommendations for how to simulate daylight in my office.

    • I don’t know if you carry any weight where you work but you might be able to sweettalk the maintenance man into installing daylight frequency fluorescent bulbs in the fixtures near your desk

  12. Awesome app for the computer! Wish I didn’t have to jailbreak my phone ):
    Be wary of the glasses that fully block out blue rays… If you’re working on a computer you may want to use “Blutech” lenses ONLY while using the computer as blue light also effects your mood cycle. There’s also another lens called Provencia that blocks enough to help with your mood cycle just doesn’t mess with your mood cycle. Not enough blue light can lead to depression and crankiness!!

    • Clarification needed here. Without a doubt, unless you’re working the night shift and need to stay alert at night, you want to block out 100% of the blue light at NIGHT. Yes, a daily dose of blue light is essential for our health, however, we should get it during the daytime… especially the morning time. Have breakfast in a sunny room, if possible, go out for a walk at 10:00 A.M. Research shows that getting a daily dose of blue light during the daytime, dramatically increases our body’s ability to produce essential and increased levels of melatonin at night.

      • Clarification needed under your comment. Blue ligh is needed when you start your circadian rhytm and trought your circadian activity, “daily dose of blue light during the daytime,” you dont need study only logic o know that if blue light is major factor in melatonin then is logical that we need exposure to regulate this hormon.

        • I’m working with a sleep specialist and this is the opinion of only one doctor. “Morning” refers to YOUR morning. “Daytime” refers to YOUR daytime. My day starts later than others and I crave sunlight because I don’t get enough natural light. I get some though. Artificial broad-spectrum light can help but I really feel sorry for all the people who work night shift. Like I said this is MY doctor’s opinion. Other people may have different ones. He also showed me why my sleep seems random – according to what he knows, cutting off the melatonin cycle doesn’t reset it, it just pauses it. We’re still confirming I have DSPD and not a non-24 rhythm.

          • “He also showed me why my sleep seems random – according to what he knows, cutting off the melatonin cycle doesn’t reset it, it just pauses it. We’re still confirming I have DSPD and not a non-24 rhythm.” pls start using brain, melatonin is regulated by light not any internal clock, internal clock is regulated by melatonin secretion, you cannot pause melatonin or reset etc. and there is no such thing like melatonin cycle its a hormon which respond to internal stimuls.

            • Darius
              Melatonin has its own endogenous rhythm and is not only affected by light but also time of day.
              You may wish to engage your own brain and do a little research before posting such harsh comments to someone who is obviously struggling circadian issues and is under the care of a sleep expert.

              • Agreed – very surprised that such a rude, unconstructive and plain wrong comment made it through moderation.

      • You bring up a couple good points, and there may be one hiding in between. Suppressing melatonin production commonly extends circadian rhythm, and shortening that rhythm needs other magic. The melatonin can only be suppressed when the circadian cycle is trying to produce it, so that permits plenty of good ole daylight.
        Circadian disruption is directly connected with several health issues, and the melatonin is connected with reducing breast cancer. The late night workers needing periodic nap time, while work time is beneath the cool-white lighting are subject to the cancer increases, not to mention circadian upset.
        A trial to feel better during circadian upset may be to overcome “Jet Lag” with 3 or more time zones. Fly East Coast to West Coast, then wish to sleep when no one else does. West to East flight has you watching the solid state TV which suppresses natural melatonin production when it finally tries..
        Tinted glasses one way, wine the other.

    • There’s also the Twilight app on Android. Not sure about other platforms. Works the same way. It’s pretty awesome.

    • Stephanie- could you elaborate a little or send me to an article where they go in depth on blocking and mood interference? I found that after wearing my UVEX glasses in the evening, when I went to bed, I was very anxious to the point of a panic attack. All I had done differently was wear those goggles so I’m intrigued if these could be related? Any literature or comments are appreciated!

  13. Another way to filter out blue light is to invest in a blue-light filtering eyeglass lens. FL-41 tint has been proven to filter out this type of light. Google it.

  14. I downloaded the f.lux app for my macbook and noticed the yellow tint to the screen that night, but never gave it a second thought. That night I slept the best I had in months. But I didn’t make the connection. I thought perhaps I had had plenty of fresh air that day. lol. The second night I also slept very well– straight through six hours instead of waking up after three hours as usual. Now I can’t deny the correlation between the app and my sleep. I just ordered a pair of the blue-blocking glasses to help me when I’m reading my phone and watching tv in bed too as I am totally convinced of the need to reduce blue light at night.

  15. Can you point me to the “Research has demonstrated that nighttime light exposure suppresses the production of melatonin”. my wife doesnt believe me on this and lets our daughter have multiple lights on a night.


    • Hey John, if you scroll to the bottom of this page http://bluelightshield.com/ you will see a bunch of links that take you to BBC, The Harvard Medical School, and the NHS website that talk about this blue light issue. Hope that helps.

  16. Amber lenses work really well unfortunately for me. I work overnights in front of a screen all day and use amber lenses to reduce eye strain, but working in a dark environment this causes my melatonin levels to go up and get sleepy to early. So overnight workers be wary.

    • Try an FL-41 lens instead of a regular Amber lens, it is specifically designed to filter out the bad part of the blue light spectrum

  17. Hi Chris,

    I bought the uvex glasses but now I have a double problem because here where I like at moment the days are shorter, for example now it is getting dark at 8 pm, in 2 months time it will get dark at 10 pm and get bright at 4 am, I do not know how the glasses will help me on this case, should I use them anyway even though is still bright for some hours and when it gets dark try to go to sleep? Or what can I do on this case in order to get a good night sleep? Cheers.

    • Wearing the glasses tells your brain that the sun has set, and it is now night time. You can put them on well before sunset and they should still help. Depending on the quality of the specific glasses you have, and how much sun exposure you get, you may even need to put them on earlier to get the same effect.

      Play with it, and see what works for you.