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Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...

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March 04, 2010

How Light Affects Our Sleep

By Mark Sisson
340 Comments

Blue Light ComputerMost people are at least cursorily familiar with the concept of the circadian rhythm. For those who aren’t, the circadian rhythm refers to our internal, approximately 24-hour cycle of biochemical, physiological, and behavioral processes. Every living thing, from fungus to bacteria to plant to animal, has a circadian rhythm. External cues called zeitgebers (what a great word, huh?) help synchronize or alter our rhythms; they include temperature, nutrition, meal timing, social interactions pharmacological interventions (medicines, drugs), and, most prominently, the light/dark cycle of the earth.

Yes, light, or the lack thereof, plays an enormous role in the regulation of our cycles, especially our sleep cycle. For millions of years, light was an objective, exogenous measure by which organisms established behavioral patterns, hormonal fluctuations, and sleep cycles. Depending on the seasons, the position of the global axes, and the weather, you could pretty much count on light, bright days and deep, dark nights. Nocturnal hunters and scavengers took the lack of light to mean “eatin’ time,” while other animals (including humans) sought shelter and slumber when night fell. Daylight meant activity and safety (since we could, you know, see everything). Fire, then, wasn’t just about cooking and providing warmth; it also allowed humans a small sliver of daylight’s safety and security at night.

Before I go on, I need to make something clear. My regular readers will have already grasped this concept, but I think it’s a good idea to reiterate it. Though it’s tempting to place us humans on another plane of existence, apart from the mindless flora and fauna that share this world, we are animals. Sure, we’re smarter and more complex than the others, but we’re still subject to these exogenous zeitgebers worming their influential fingers into our subconscious and fiddling with our circadian rhythms. Our tendency to get sleepy when night falls isn’t a cultural relic; we didn’t consciously decide to start sleeping at night because it was too dangerous to be out in the dark. The culture of standard bedtimes arose organically, if you can even call it culture. Does the chirping of birds in the morning reflect cultural tendencies? Is “the early bird gets the worm” a standard axiom in avian academia? No – the early bird’s evolutionary niche decrees that it wake up bright and early in order to get food. It’s basic natural selection, and humans are the same way. We don’t decide to get up early. We get up early because of a complex pattern of environmental cues telling us to get up. Throughout our evolutionary development, handling business during the daytime was simply how we survived. We can’t escape nature.

But boy do we try.

The zeitgeber (can’t get enough of that word) with the biggest impact on our sleep cycle is light. Period. And it’s not just natural light that affects our sleep cycle, but also unnatural, manmade lights. That’s kinda how we operate, actually, as instinctual beings who often misinterpret “unnatural” because, well, our physiology isn’t exactly intelligent. It’s not sentient. It’s purely reactive. Blue light from a 10:00 AM sky, blue light from your computer screen at midnight – it makes no difference to our circadian rhythms. It’s all the same to our bodies, because for millions of years blue light meant daylight, not a late night blog comment section or reruns of The Daily Show. And it’s the blue light specifically that appears to monitor our sleep patterns the most.

Like insulin and inflammation, blue light is integral to our health – in the correct amounts. When we’re exposed to levels of anything in excess (or too little) of what we would have experienced for the bulk of our evolutionary history, problems arise. Blue light regulates our secretion of melatonin, the sleep hormone. Exposed to blue light, we limit the production of melatonin, and we stay alert and awake; in the absence of blue light, melatonin production ramps up, and we get sleepy. This system worked quite well for a long time. Reddish light from fire (our formerly primary source of nighttime illumination) has little to no effect on melatonin production, so sleep wasn’t disrupted when we relied on fire. These days, though, we’re subject to a steady barrage of blue light. During the day, blue light (natural or unnatural) isn’t much of a problem because we’re supposed to be awake, but at night, when we’re “supposed” to be getting ready to sleep, we tend to sit in front of blue light-emanating appliances, and our sleep suffers for it.

(An interesting note on how we respond to blue light. For years, scientists assumed circadian rhythm was set by sight (of light) alone. Person sees sky/LCD screen and the same visual system that allows colored vision determines the hormonal, behavioral, or other physical reactions to the light. It makes sense, but that’s not how it works. It turns out that there exists a second, more dominant system responsible for setting circadian rhythm based on light input. If a person’s sleep cycle depended purely on traditional color vision, we’d expect the blind to universally suffer from disrupted sleep. They do not, however, and this is explained by optical cells that express a photopigment called melanopsin. Unlike the standard rod and cone opsins, melanopsin doesn’t help us see. Instead, it reacts most strongly to blue light, and scientists think it’s the primary regulator of the biological clock and production of melatonin. In otherwise blind patients with intact melanopsin systems, blue light has a strong effect on their sleep cycles.)

Blue light has its place, of course. A British study found that blue light-enhanced white lights in the workplace improved alertness, performance, and even nighttime sleep quality in employees. That’s during the day, though, when blue light exposure is normal and expected. Nighttime exposure to blue light disrupts our sleep hormones. Television, computer screens, even digital clocks with blue numbers – they’re all common sources of late night blue light that can affect our production of melatonin.

Is blue light the only issue? It certainly appears to be the primary driver of circadian rhythm, but it’s not the only one. In a recent study, researchers found that while monochromatic blue light suppressed melatonin production via melanopsin stimulation, polychromatic white light (which includes blue light) stimulated melanopsin equally while suppressing melatonin to an even greater degree. Clearly, it’s not just blue light’s effect on melanopsin affecting our sleep cycles.

Still, blue light is the low-hanging fruit, and there are some simple steps you can take to mitigate its late-night effect on your sleep.

  • Keep electronics usage to a minimum or completely eliminate blue light (alarms, TVs, laptops) after dark.
  • Go to sleep earlier.
  • Use candlelight (read how a fellow MDA reader gave this a try for 30-days).
  • Keep your room as dark as possible and your sleeping quarters pitch black.
  • Install F.lux (totally free) on your computer to cut down on blue light emissions.
  • If you want to try a somewhat extreme experiment you could even wear orange safety glasses at night.

(Thanks to this thread on PaleoHacks for the last two tips.) Also, don’t forget to expose yourself to blue light during the day so that your cycle normalizes – it goes both ways, you know.

Does anyone have experience cutting out blue light exposure to great effect? Let the world know in the comments.

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340 Comments on "How Light Affects Our Sleep"

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Organic Gabe
6 years 6 months ago

Candlelight is a good idea. And my wife will like the new romantic atmosphere….

animal (ex-firefighter)
animal (ex-firefighter)
6 years 6 months ago

Just be safe… candles and unattended cooking are the top two causes of house fires.

Johnny at The Lean Saloon
6 years 6 months ago

Yes, good advice. My concern is not an unattended candle so much as it is our cat walking by it and catches its tail on fire, jumps off the counter and dashes into the curtains.

But I do love the candle idea, and my wife has a huge collection of them. Now that I’m ready to experiment with candle light at night, we’ll have an amalgamation of senses that include vanilla, cinnamon, wild berry, velvet, lavender, and midnight jasmine.

Can an aroma ambush stimulate the sympathetic nervous system?

kimelah
kimelah
4 years 11 months ago

re: cat’s tail knocking it off and/or curtains – that’s why I’ve started buying/acquiring on-the-wall candle holders that hold the candle INSIDE it, in a glass jar.

Also, I only use beeswax candles. I love the smell, and it’s NOT petroleum.

john
john
5 years 8 months ago

poor electrical work is the top cause of house fires

Todd
6 years 6 months ago

I love the candlelight idea. And even if it is artificial light…. if you use only a few candles then the amount of light that is produced is significantly lower then the amount of light that is produced with several lightbulbs and a glaring TV, computer, or whatever.

When the sun goes down, our body naturally begins to go into sleep mode. It may take a couple of hours, but when its pitch black its sleep time!

docbets
docbets
6 years 6 months ago
Candle light does not allow a person to do anything. Wash the dishes? Read? Take a shower? Please. I used to use kerosene lamps back in the 60s, but probably they emit poison gases. And if you turn them up high enough to read, they smoke up the chimney. And the room. And the smoke keeps the light from coming through. But it is a warm (not blue) light. Even so, unless we are to retire when it gets dark, we will be using electric lights. In northern areas, it gets dark in winter at 5 pm. I wonder about… Read more »
Jonathan
Jonathan
6 years 6 months ago
“unless we are to retire when it gets dark, electric lights” Electric yes. But we can more wisely choose which ones. Don’t buy the 6500K bulbs for night time use. I’ve got a lamp with two independent sockets/switches. A regular bulb in one and a 60watt equivalent florescent yellow “bug” light in the other so I can choose which to light depending on the time. The bug light is more than enough to read or do anything by. My 2 year old daughter cried wanting to go to bed the first night we tried it and has stopped fighting to… Read more »
fgd
fgd
3 years 10 months ago

Wash the dishes? Check. If you’re meticulous, you could do it with your eyes closed.

Read? CHECK. People used to read under candlelight all the time. It’s totally sufficient.

Take a shower? Check. I always shower with the lights out, actually. I can’t imagine why you’d think it would be a problem.

Tanya
Tanya
1 month 10 days ago
I frequently bathe with 2 dinner candles lit, and can easily read by those whilst taking a long bubbly soak. This began by being annoyed by the automatic vent system in my bathroom that turned on with the light, it was too annoying to read with that on. I imagine if one is careful one could easily wash dishes by candlelight; I always put sharp knives off to the left in the sink, so that even under suds I know where they are, move the hands slowly that’s all! I mean, how do completely blind people wash their dishes? Carefully!… Read more »
WG Newman
5 years 2 months ago

I totally agree with this. People have no idea what they are doing to their bodies and will die accordingly.

JL
JL
3 years 10 months ago

I sleep with a black lite on my 1960 posters in my bedroom . I sleep like a log.

Jackie
Jackie
1 year 8 months ago

There is preventative blue light screen protector that can be purchased usually from websites such as http://bluelightshield.com/

Peggy
Peggy
6 years 6 months ago

“zeitgeber” time giver… if my german is correct. They come up with some marvelous compound words.

Annette
Annette
6 years 6 months ago

Yes, literally it’s “time giver” but it means “timer” 🙂 Makes sense!

Rodney
Rodney
6 years 6 months ago
Very interesting! I will be interested to hear all of the comments on this. When I read “Lights Out” several years ago, I wondered about fire at night, moonlight, bright stars etc., and why they wouldn’t have disrupted melatonin in Grok’s time. Maybe the blue light theory explains this?? Also, “Lights Out” mentioned that just a small amount of light from a fiberoptic scope shined on the back of a knee was enough to cause problems, so apparently it isn’t just receptors in the eyes that matter. Lastly, I am wondering how latitude affects melatonin comparing someone on the equator… Read more »
Kishore
Kishore
6 years 6 months ago

With the insanity of Facebook status updates (for all the self-important people) and twitter being logged in every few nanoseconds, staying away from an electronic device seems impossible for the tech-crazy Gen-X. Just go to any mall in America and looks at the teens, muffin tops busy on their cell phones. No to mention teenage boys castrating themselves with radiation from cell phones and frying their testicles with video games and not making any testosterone. Pretty soon, they would all be sitting and wathcing Oprah eating tofu burgers (or maybe they are).

Dr. Surf
Dr. Surf
5 years 2 months ago

re: electronic devices, cell phones, etc.: You nailed it! Even though there is ample evidence that prolonged up-close cell phone use can create tumors, half the population seems to have a cell phone stuck to the side of the head (with crazy glue?). “Darwin Award” candidates abound, so hopefully the situation will prove to be self-regulating. (Says he, typing this message on his laptop… 😉 )

Row
Row
4 years 2 months ago

There is no ample proof that cell phones cause tumours or any type of cancer.

If this was the case wouldn’t we see the rate of tumours increase.

It’s common knowledge that heat will reduce sperm production, however if you wear briefs you are just as likely to reduce your sperm count….

Username
Username
6 years 6 months ago
I have bipolar disorder and it used to really wreak havoc with my sleep cycle, until I started wearing copper safety glasses after 6pm and a sleep mask at night. The glasses were a huge pain to get used to (and the sleep mask took time too), but it made a big difference. During the winter, I also use a lightbox for about 20 to 30 minutes every morning. This has pretty much completely normalized my sleeping routine and my energy levels. Incidentally, other bipolar symptoms are also much easier to manage and I seem to be in “remission” (symptom… Read more »
Lynda
6 years 6 months ago

Hello — I see that you are one of millions that have bought into a label of “bipolar” disorder
Only YOU know you — being labeled with a “disease” that can not be actually proved through ANY scientific method begs the question? Is this a disease or not I recommend you look at this – only if you are interested in answers
http://www.cchr.org/#/book/documentaries/marketing-of-madness-dvd-english

Kelda
6 years 6 months ago
I think this is a rather sharp response. I will go and read your link, but I would say this. My grandmother was treated for, what was known then as ‘manic depression’ through her early adulthood onwards, this included EST, not something I would wish on anyone. She died age 56 from complications of uncontrolled diabetes. I was insulin resistant during two pregnancies so although not considered diabetic non gestationally clearly have a predisposition to metabolic sensitivity. The fact that I have hugely benefited from insulin control through Primal eating and have, for many years worked with swings that are… Read more »
Kelda
6 years 6 months ago

I’ve just followed your link – I do not take any form of drug, I have never followed the CW on this, in fact following the history of my Grandmother’s treatment from CW (which was effectively to foreshorten her life) my family ensured I was never seen by the ‘establishment’. I have worked with an altenative thrapist at a cognitive level, not with any form of drug and have ‘learned’ my way through it. Keeping insulin low on Primal has been THE most effective ‘treatment’.

Mickey
Mickey
6 years 6 months ago
I am a rehab counselor for folks with dual diagnosis–meaning they have substance abuse issues and a “mental illness.” First, I want to say that I respect you and your family’s decision to forego any pharmacological interventions. I think it would be tempting to follow the CW and its promises of miracle cures. While I do believe that mental illness does occur, I wish I had the freedom to experiment with nutritional and lifestyle treatments. It sounds like you have experienced some good success by changing your habits! I personally have complaints about the convergence of the psychiatric and psychological… Read more »
Kelda
6 years 6 months ago
Mickey (I hope this posts appears below yours) Thank you very much for your comment. It takes a great deal of bravery for many like Username above to speak more openly about this and it’s great to read a sympathetic post. I too passionately hope that further, proper, investigation of the effect of nutrition on a whole myriad of modern ‘conditions’ begins to pick up speed, from what I see around me the long term healthy survival of our species may well depend upon it. Since beginning this journey after a chance encounter with a guy on a ferry back… Read more »
Diogenes
Diogenes
5 years 2 months ago

Don’t you love it when people who don’t have the problem ridicule you for having it? Don’t let Lynda’s smug criticism get to you. The internet is, unfortunately, a haven for the self-anointed. In fact, such people may (or may not) be partially correct, but they pollute their message because they can’t resist telling you how cool they are and, in contrast, how dumb you are. Which would seem to indicate a personality disorder. (Unless, of course, you don’t “buy into” the concept of personality disorders.)

Justine
Justine
4 years 8 months ago

Gee, Lynda, I wonder which segment of BigPharma Avicenna was working for when he described manic depressive psychosis in the 11th century. Who was Soranus of Ephesus in the 2nd century working for? The conspiracy goes back centuries!

Ordinarily I avoid responding to comments where all capitals are used. However, the stigma of bipolar disorder is bad enough without additional counterproductive suggestions that a syndrome that occurs in all countries and devastates many lives is imaginary.

Kelda
6 years 6 months ago
I too have bipolar disorder, I have lived at 57 north (northern Scotland) for the last 10 years. During our longest days it never really gets dark – you could read a newspaper in the garden at 2 am – and during the winter we only have about 6 hours of true daylight. This played havoc with me for the first few months (I arrived in August). Once I started using an eyeblind it helped a bit. However, what has really helped with the bipolar symptoms is turning Primal, in November last year, since Christmas I’ve seen a huge improvement,… Read more »
Jonathan
Jonathan
6 years 6 months ago

When my blood sugar is on the way down from a high (not anymore since I’ve cut the carbs), I would get so irritable and mad at every little thing including myself. Blood sugar has a HUGH effect on mood.

R
R
1 year 5 months ago

I too lived at 57N for nine years and I always had trouble sleeping during the height of summer. In the middle of June it never got darker than twilight the whole night (been at midnight) and even during the winter where it gets dark very early, the full moon sometimes made the skies barely darker than in summer!

trackback

[…] Original post by Mark Sisson […]

Nic
Nic
6 years 6 months ago

Holy crap, this could explain why I have so much trouble falling asleep in my college dorm: I have a nice dark loft, but my alarm clock is this bright blue monstrosity. I find I need an alarm clock because using my cell phone just does not cut it. Should I just settle for one of those red LED’s or does anyone know of any better options?

Wendy
Wendy
6 years 6 months ago

I bought a battery powered clock that only lights up when you tilt it. It’s nice not having red, glaring numbers in my face all night. And if I need to know what time it is at night, I can easily find out. It also has an alarm clock, but I have a two year old that wakes me instead.

Susan
Susan
4 years 10 months ago

What kind of battery powered clock do you have? I need to get a new one for my husband and have searched but can’t find one that tilts to light up. Only ones that are on continuously which I do not want.

Thanks!

Matt
Matt
6 years 6 months ago

You could also go old-school and get an analog alarm clock that rings a bell when it’s time to wake up.

LV
LV
6 years 6 months ago

I remember reading a while ago about an alarm clock that you wear on your wrist like a watch. You set it to a time range that you want to get up and it detects when you’re in the lightest phase of sleep during that time and wakes you then. Supposedly it’s less stressful than being woken from a deeper sleep, which makes sense I guess. Can’t remember the name of it, sorry, but could try googling it. Not cheap though, as I recall.

Real
Real
6 years 6 months ago

It’s called the “sleeptracker” and I have an older one. It works very well and I wake from a nice light sleep. Gone are the days where I am wioken up right in the middle of a deep sleep and spend the rest of the morning grumpy and tired.

Ryan
Ryan
6 years 6 months ago

Or if you have an iPhone you can download an app for 99 cents that does the same thing and includes a chart of your sleep every night. The iPhone contains the same movement detecting hardware as that watch, you are essentially just downloading the software. Top app in several
countries. Sleep Cycle
http://itunes.apple.com/us/app/sleep-cycle-alarm-clock/id320606217?mt=8

Tami
Tami
6 years 6 months ago

I just cover the face of my alarm clock with a heavy towel or washcloth. Works great!

piano-doctor-lady
piano-doctor-lady
6 years 6 months ago

My alarm clock has red numbers, but I put it on a low shelf next to the bed, almost on the floor. If I want to see the time, I have to prop up on an elbow and look down at it.

And I never set the alarm. I use a lamp with a 60 watt incandescent bulb on the far side of the room, with a lamp timer to turn it on and off.

paleo-curious
3 years 11 months ago

I have an alarm clock/ cd player & an iPod dock by my bed, both with bright blue displays. I bought some cheap red photographer’s gel samples & overlaid them on the light-emitting areas. Amazing difference! Now I can have my sounds & sound sleep too!

Mike
Mike
6 years 6 months ago

This really explains why I have a harder time sleeping (generally) when my cell phone is face up on my nightstand, it constantly emits a low light. How weird.

Shane
6 years 6 months ago

Hmmm…I might have to ditch the alarm clock I got for Christmas with huge, bright blue numbers on it.

misathemeb
6 years 6 months ago

i believe in this so strongly! so much so that after it gets dark, i put the laptop away and dim the lights in my living room until it’s my “bed time” my bedroom has no light in it and it’s a perfect sanctuary! i also feel like i’m one of the few who do not have a tv in there. the bedroom is NOT a tv room, it’s your place of rest!

hannahc
hannahc
6 years 6 months ago

misa we don’t have a TV in our bedroom either, and likely never will! We’ve talked about it a few times, and have already decided that one TV in the house is enough.

poo
poo
4 years 11 months ago

thats cuz ur poor and cant afford more than one , get a better job pussy

berian
berian
4 years 9 months ago

anybody got a cookie for the troll LOL

Michelle
Michelle
6 years 6 months ago

Years ago, I read about the glowing numbers on alarm clocks disturbing sleep, so I have since turned the clock away from me at night time, and it really does make a huge difference. BTW, having even dim light on during sleep has also been proven to be detrimental to long-term eyesight.

Jack
Jack
6 years 6 months ago

Really? Do you have a cite for that? I do not believe that dim light during sleep has ever been proven to be detrimental to long-term eyesight.

docbets
docbets
6 years 6 months ago
Problem with all these electronics, though, especially turned around to the back, is the EMFs they emit. Those will disturb sleep a lot. I use a windup alarm clock, Big Ben. And if we were really getting enough sleep to begin with, we would not need an alarm clock to wake up at all. I have read that the way to resume getting proper amounts of sleep is to sleep til you wake up – usually people have to use vacation for this – and keep doing that until the sleep debt is paid off. Eventually, a person will wake… Read more »
PHK
PHK
6 years 6 months ago

yes, if we’re awaken up by any external forces (alarm clock, phone ring), then we really don’t get enough sleep.

sleep is a weird thing that we can only pay debt; we can’t store it when we’re not sleepy & withdrawl it later, like food & drink.

but sleep until naturally wake up does work for people who have DSPS tho.

regards,

Jonathan
Jonathan
6 years 6 months ago

So what if I change all my lights in my house for those yellow/orange “bug” lights of a lower wattage?

piano-doctor-lady
piano-doctor-lady
6 years 6 months ago

I don’t think you’ll have to do that. I picked up some 13 watt “whirlie” bulbs which said they were “soft white.” Really, they’re yellower than an incandescent bulb. Equivalent to a 60 watt. I put one in the reading lamp over my bed last night, and was very struck with the difference. I thought it would be too dim, but I read a book without trouble by it.

piano-doctor-lady
piano-doctor-lady
6 years 6 months ago
I forgot to mention something else. In the kitchen, I have deep yellow walls between the cabinets and the counters. I just bought “rope lights”, which are quite yellow, and I’m mounting them under the cabinets, one rope on each side of the sink. In the evening, they give enough light to putter around, and to have a background to the TV, but the room is bathed in a dim yellow glow, very soothing. I may try getting one of those orange TV filters as well. The rope lights draw 8 watts apiece. They were intended to be Christmas lights,… Read more »
DarthFriendly
DarthFriendly
6 years 6 months ago

It’s funny, but since starting PB 14 days ago I’ve been going by a “lights out” policy after dark, and it’s helped my sleep immesurably. I was just doing this intuitively. When I get home at night, I only turn on the lights I need for a specific task, like washing the dishes, or cooking something, or a small reading lamp to read. I websurf in the dark (probably not the best thing ever) and now have no trouble falling asleep. Before I would have to take melatonin or lie awake for hours. The change has been very dramatic!

Matt
Matt
6 years 6 months ago

When I saw this headline I immediately scrolled down the page to see if you had mentioned F.lux. I can’t endorse F.lux strongly enough. It has had a huge impact on my quality of life since I installed it.

piano-doctor-lady
piano-doctor-lady
6 years 6 months ago
I installed f.lux yesterday after reading the article! Yesterday evening, for the first time in living memory, I spent a couple of hours on the computer, and by 9:30 p.m. I was bored with the computer and wanted to curl up with a good book in bed. By 10:00 I was ready to turn out the light. I had read years ago in “Lights Out” that sleep before midnight is worth much more than sleep after it, but never was able to get to sleep until almost midnight. This f.lux program is WIZARD! Mark gets a real vote of thanks… Read more »
Justin
Justin
6 years 6 months ago

It’s great to see some recognition for the importance of circadian rhythms. I did my MS in a circadian physiology lab, and am now doing my PhD work next door to the guy who discovered melanopsin. Light is very important (but you have to take the light intensity WAY down to make a significant difference), but you would be shocked at how much feeding patterns can play into sleep cycles as well. Even subtle fluctuations in temperature can make a big difference. Of course, it is mostly impractical for the average human to take those things into daily consideration.

Logi
Logi
6 years 6 months ago

Justin,

Can you provide more information about issues that affect sleep? It sounds like you are working right next to a world class researcher and aren’t doing shabby yourself! We should take advantage of this. Everyone here is jumping into changing lightbulbs… and no one replied to your post.

Can you provide more detailed responses to Mark’s article? Are there other ways to get better sleep? etc.

Thanks!

rtegan
rtegan
6 years 6 months ago

One sleep related word that I really like is Suprachiasmatic Nuclei, or SCN for short. That’s the region that is taking all the light waves in and telling your brain to either take a break or wake up.

Luke
Luke
6 years 6 months ago

As far as orange glasses go, here is an alternative site:

http://noir-medical.com/filters/index.html

Luke M-Davies
6 years 6 months ago
Fascinating stuff Mark. I always love the variety you bring to MDA! For a long time I have been strict on keeping light levels low at night – I’m really sensitive to it and thought I just had paper eyelids or something. When I’m sleeping in a new room, I always have to cover LEDs if I cannot turn them off. I think some of it is psychological, because then I can relax but you have given us the sciene behind it! I even have 2 pairs of curtains in my bedroom to try and block the streetlight. I have… Read more »
shannon
shannon
6 years 6 months ago

What about the lunar cycle? Some people think that it’s good to expose yourself to varying degrees of moonlight, as ancient people were. It’s supposed to regulate your menstrual cycle if you have one. I can’t really block out all the outside light when I’m in my city bedroom, but in the country I can. Still, in the country, moonlight streams in on some nights.

Athena
6 years 6 months ago

I know when I dont get enough sleep (especially if i accidently leave my laptop in the bedroom and the charging light is going on the whole night) I get super grumpy! Now ill try to cover all lights in my bedroom, lets see if it helps.

shastagirl
shastagirl
6 years 6 months ago
thanks for the link f.lux!! i just installed it cant wait to see it work around 9pmish, although i plan on being in bed close to then. i was reading a few excerpts from the book lights out, which i ordered online yesterday along with a copy of mark’s book (finally), and the vegetarian myth. 40 bucks delivered for 3 books what a bargain! ill never shop at b&n again, went in and they didnt have any of the 3. in fact vegetarian myth didnt even show up in their computer search! anyways i was very happy to find this… Read more »
CraigBC
CraigBC
6 years 6 months ago

Sleep is incredibly important to our overall health. I agree with the idea that artificial light may be as bad as artificial foods.

One of my goals in life is to find a community that mandates all lights out at night besides candle/fire light. There is a place in New Zealand that is like this. The stargazing must be absolutely amazing.

MicheleQ
MicheleQ
6 years 6 months ago

Great entry! I would add that it’s not just the blue light but also the electromagnetic radiation that can disrupt sleep –never mind all the other things it’s doing to our bodies.

Ms. S
Ms. S
6 years 6 months ago
My husband and I have been wearing ‘Blue Blockers’ for two weeks now – starting around 8 pm. Now they’re not the coolest looking things in the world, but the effect on our bodies and minds is incredible. We start to ‘shut down’ within a half hour of wearing them. F.lux – as great as it is – matters even less because I suddenly can’t muster the energy to look at the computer any longer. Where we were once night dwellers, never getting in bed before 12, we are now solidly asleep by 10 every night. Great, timely post Mark!
Mr S.
Mr S.
6 years 6 months ago

In fact it was my (the husband) comment on Paleohacks that had the link to the orange safety glasses.

I have to say I wouldn’t be caught dead outside the house with the glasses on and avoid standing near our windows where our neighbors could see us while donning them. They have more stylish, and more expensive, blue blocking glasses at lowbluelights.com.

The effect the glasses produce is very dramatic. It was definitely worth the $10 just to experience it.

Sterling
6 years 6 months ago

This line is very interesting: “Reddish light from fire (our formerly primary source of nighttime illumination) has little to no effect on melatonin production, so sleep wasn’t disrupted when we relied on fire.” When hanging out around a fire (at my buddy’s ranch for example – a huge bonfire), it’s relaxing, mesmerizing, and therapeutic. Maybe the reddish color of the fire has more to do with it than we ever imagined. Very cool and interesting info.

Rodney
Rodney
6 years 6 months ago

I downloaded F.lux and it should activate in about 20 minutes here. I also found that an old pair of cycling glasses have an orange lens I can use in place of the regular one, so I am re-activating those glasses just to see what happens.

I wonder if F.lux helps at all if you are still exposed to tv, and regular lighting in the evening, but don’t have any special glasses on? It just seems too easy to get 95% of this right and have the 5% I miss negate all of my efforts.

Mr. S.
Mr. S.
6 years 6 months ago
Before we got our safety glasses I tried a pair of regular sunglasses I own that have a orange/amber hue. They didn’t really have any effect. I bought those glasses Mark linked to because I came across them here while reading up on the effects of blue light: http://psycheducation.org/depression/LightDark.htm. Also, you can see they are the same as the pair in the pic at http://www.lowbluelights.com even though that site doesn’t sell them. When put these on things that are very blue appear almost black because they block a large percentage of the blue light. My understanding is that few minutes… Read more »
fixed gear
6 years 6 months ago

I think you guys are over-complicating it. Just turn blue-light emitting stuff OFF when you want to go to bed!

thecarla
thecarla
6 years 6 months ago
I read Lights Out several years ago and have always been concerned about all those appliances with lights emanating out of them. I am now living alone after several years and it is so difficult for me to sleep in a pitch black room, I start hearing all kinds of wierd noises, but I know when I do turn the lights off and the computer off, turn my alarm clock around and my cell phone off I feel better. When I don’t get enough sleep I am like another much older and decrepit person. I am definitely trying some of… Read more »
Jonathan
Jonathan
6 years 6 months ago

Try a fan in the room. It will cover the creaky house noises.

Pamela
Pamela
6 years 6 months ago

Last month (partly to keep the cold out) I took a very heavy very dark colored blanket (not very decorative) to cover the windows in my bedroom.

Since doing so, I sleep better because the room is pitch black. I also noticed that I sleep longer on the weekends averaging 8-9 hours instead of 5-7.

Also, every night, my phone shuts down at 10pm which is my bedtime so I won’t get the annoying text from someone who really has nothing to text about.

fixed gear
6 years 6 months ago

If you cover all the windows so it’s pitch black, how do you ever wake up?? Don’t you need that sunlight coming in? If my room was truly pitch black I think I’d sleep till noon.

Jon
Jon
6 years 6 months ago

Is there anything like f.lux for room lights?

Candles are not a practical long run solution for me, and I’m concerned about the fire risk as well as indoor air pollution. Going with no artificial light would be ideal, but it’s difficult to wrap everything up by sundown, especially when there are others in the house.

Therefore, if there were a way to automatically switch all overhead lights to ‘red mode’ after sundown, it would be an easy way to correct melatonin deficiency.

piano-doctor-lady
piano-doctor-lady
6 years 6 months ago

If you get the “soft white” compact fluorescent bulbs, really, they are quite yellow. I’m changing over to them exclusively in rooms where I spend evening hours. Also trying the orange glasses. “Chromalux” bulbs also have a lot of red in them, and radiate heat, so they’re nice to use in a cool room in the winter.

Matt
Matt
6 years 6 months ago

I’m totally buying a fire pit. Thanks for the inspiration.

Kat Eden
6 years 6 months ago
I’ve been an advocate of preserving sleep in order to enhance health, manage weight etc for years but hadn’t heard of the whole blue vs other light thing. Thanks Mark, very interesting. I have to say, I suffered insomnia severely for 3 years and one thing that did help (among other methods) was to force myself to cull the TV and computer a couple hours before bed. I think if people realised how much lack of sleep affects every element of their metabolism, health and wellbeing and not just their energy then they’d be far more motivated to do something… Read more »
JD Moyer
6 years 6 months ago

Great post — glad to see this topic getting more attention. Sleep deprivation and excess sugar seem to have near identical negative effects on the body and endocrine system.

Thanks for the mention! I’ve just posted a detailed description of our “Month Without Artificial Light” experiment on my blog. There were both positive and negatives. The New York Times article I link to and quote from is a must-read for anyone interested in this topic.

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[…] MDA – How light affects our sleep […]

Jess
Jess
6 years 6 months ago

What is the difference between these blue light blocking yellow lensed glasses and yellow lensed night driving glasses? http://www.google.com/products?q=yellow+driving+glasses&rls=com.microsoft:en-us&oe=UTF-8&um=1&ie=UTF-8&ei=3rSQS_GtG4jkNYuzrKQN&sa=X&oi=product_result_group&ct=title&resnum=1&ved=0CCAQrQQwAA it seems to be easier to find the driving glasses, if they are essentially the same it seems much more frugal to go for the night drivers… any thoughts?

Mr S.
Mr S.
6 years 6 months ago

They appear to be much more yellow than the orange cooper safety glasses. The orange cooper glasses block something like 90% of the blue light.

I didn’t get much of an effect from some sunglasses that were fairly orange so I don’t think driving glasses will cut it.

The safety glasses are only about $10. If your looking for something more comfortable or stylish you could give the cooper’s a shot first to see how it works for you.

Kelda
6 years 6 months ago

One thing strikes me, if they are night drivers surely it wouldn’t be safe if they were blocking light that might keep you awake, as being awake might be quite important when driving!

PHK
PHK
6 years 6 months ago

I read a hypothesis of evolutionary a that small percentage of our ancestors were natural owls so they could guard others against predators during the nights.

then i must be a descendent of them. haha (light therapy does not seem to work too well for me as my circadian clock is not very sensitive to light.)

Dan
Dan
6 years 6 months ago

I’ve read that hypothesis too, Brain Rules? I hope it’s not true or I may be screwed. I’ve always had trouble falling asleep.

The one thing that has helped me fall asleep is heavy exercise during the day. Though I usually end up ‘napping’ for 2-3 hours right after a long surf session and that makes me stay up later lol

Thanks for the suggestions Mark!

PHK
PHK
6 years 6 months ago
hi, Dan, are you insomniac or you’re just not tired? i am not insomniac. i can fall asleep in 5-10 min if i’m tired (which is between 1 & 2 AM) i am just not tired at all. so it feels very wasteful to me to toss in bed during my prime time when i feel most productive & alert. (i think it’s called “delayed sleep phase”. maybe you have it too. I just downloaded f.lux. i hope it works. like i said, light in the morning does not wake me up. i could sleep in a bright room in… Read more »
PaleoMum
6 years 6 months ago

My 6 year old is scared of the dark and insists on having quite a bright nightlight… should I be putting a red bulb in it? Will that help?

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[…] aware of light sources when you turn in for the night – you can drastically improve your sleep […]

Brett_nyc
Brett_nyc
6 years 6 months ago

Thank you so much for this article Mark. Definitely an Aha! moment for my fiance who has massive trouble falling asleep and coincidentally is on a laptop until late at night.

Joshua B.
6 years 6 months ago

Has anyone tried to change out all of their light bulbs to non-blue light emitting ones? That was the first thing that came to my mind after reading this article..thanks Mark!

Jonathan
Jonathan
6 years 6 months ago

I just bought two yellow “bug” lights at Lowes. I check there and Wal-Mart but neither had one less than 60watt so the 60 is what I got. No amber night-lights either. I’m trying those bug lights out tonight to see if I should replace more of them. (I tried candles last night but the parents were over and we needed the lights and then later as I’m heading to bed the wife turned the lights on to get ready for bed which made me angry.)

NickW
6 years 6 months ago

I put F.lux on my computer, and now actually get sleepy during my late-night Stumble/blogging sessions. Wonders for my sleep schedule.

Great post!

jk
jk
6 years 6 months ago

Thank you for posting this! Your explanation of the types of lights is so much more helpful than the typical ‘don’t sleep with the tv on…don’t keep your cell phone next to the bed’ you see in tips for a good night’s sleep articles.
I downloaded f.lux last night and began yawning within minutes (okay, it was seconds!) and I went to bed early. Also for the first time in years, I tried and succeeded at falling asleep without the tv on. Thanks again!

piano-doctor-lady
piano-doctor-lady
6 years 6 months ago
I also found that Vitamin B12 status matters a lot to melatonin production. (People without enough Vitamin B12 don’t make enough melatonin.) Older people often have trouble absorbing Vitamin B12. When I tried the methyl form of B12 (under the tongue) I started sleeping like a log! And much longer at night. The bedroom has to be really dark, of course. I prefer the Jarrow brand of methylcobalamin, but others no doubt are all right as well. Vitamin B12 also improves small muscle coordination. I read that Olympic marksmen take methyl B12 because it eliminates a tiny tremor and improves… Read more »
frank
frank
6 years 6 months ago

Flux is SICKKKKKK Thanks mark

Luke
Luke
6 years 6 months ago

After looking carefully at the melatonin study statistics, It seems that the sample size was extremely small: n30 to be even more convincing.

Ryan Denner
6 years 6 months ago

I did the candlelight thing last night – it worked SO well.

Gary-A
Gary-A
6 years 6 months ago

I JUST INSTALLED FLUX AND IT IS AMAZING! I seriously just spent ten minutes sitting here turning it on, turning it off, turning it on………..

Kate
Kate
6 years 6 months ago

For some strange reason, I can’t get Flux to download. I think maybe it’s our apartment complex’s firewall that I can’t get around. Can someone e-mail me the .exe file so I can install it?

supercanid (atsign) gmail (period) com

Thanks in advance!

Benjamin Skipper
6 years 6 months ago

I have not purchased one of these (but plan on doing so), but for those considering replacing their alarm clocks you may like this:

http://www.costco.com/Browse/Product.aspx?ec=BC-EC9433-ProdID11485608&pos=1&whse=BC&topnav=&prodid=11487201&lang=en-US

It’s a “daylight” clock that simulates a sunrise, so it attempts to wake you up by assisting with serotonin production rather than with a loud noise. I really like the idea of it since I room in a basement right now, so I have no way as of current to wake to sunshine on my face. Saving for it!

Cullen D.
Cullen D.
6 years 6 months ago

That looks expensive! Cheap people (like myself) could perhaps attach a cool-temperature (i.e. florescent, LED) light to a wall socket timer for almost the same effect.

Matt
6 years 6 months ago

The Candlelight trick seems to work well. For more info on daily health including diet and tips see our blog.

Anne Scott
Anne Scott
6 years 6 months ago

I installed Flux but now nothing happens when I click on it (I want to change the settings) — anybody else having this problem? There are no answers on the Flux page, tho many people have also asked the same question there.

Jess
Jess
6 years 6 months ago

go to your bottom right hand icon tray and click on the icon there and see if that works.

Hollie
6 years 6 months ago

Are you using Windows or Mac?

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