Is Blue Light Making Dry Eye Worse?
This is a great question no one has assessed on published about thus far.
Many eye surgeons are concerned about the long term macular damage electronic screens, which through their almost universal Light-emitting diodes (LEDs), emit concentrated blasts of blue light on to your retina. 1
For more health news, keep reading:
This is a great question no one has assessed on published about thus far.
Many eye surgeons are concerned about the long term macular damage electronic screens, which through their almost universal Light-emitting diodes (LEDs), emit concentrated blasts of blue light on to your retina. 1
Many eye doctors are now recommending and using blue blocking computer glasses. There is no published paper out yet to prove the need for this, but many of us are concerned.
Thus it was a surprise when a surgical colleague asked me if blue light is making dry eye worse. It seemed at first like an unlikely cause. Yes we know that patients do not blink fully and blink less when they are concentrating looking at an electronic screen. But is it possible that the blue light is damaging the blood vessels around the meibomian glands?
There are no studies looking at this particular issue that I could find. But I did find a study that noted that blue blight shined on newborns was not necessarily a good idea as it potentially increased mutations in DNA/genetic material: This is not a definitive proof that blue light is making dry eyes worse by a long shot, but it was of interest and I will research this more.
—-
‘Recently, damage to genetic material has been observed in newborns exposed to phototherapy [12–15]. Similarly, an increased number of micronuclei in circulating erythrocytes MNE was observed in PNBs, with the highest number of MNE observed in PNBs with more exposure time to phototherapy, but not oxygen therapy [15]. Prolonged phototherapy exposure has been associated with increased oxidative stress, lipid peroxidation and riboflavin deficiency [16].
The visible white light spectrum ranges from approximately 350 to 800 nm. Bilirubin absorbs visible light most strongly in the blue region of the spectrum, which is at approximately 460 nm [16]. Thus, one question that arises is whether all phototherapy lamps increase the number of MNE or whether this effect is due to specific lamps.
The wavelength of blue light is above 400 nm [17]. The emission of light in the blue-to-green range overlaps the in vivo plasma bilirubin absorption spectrum (approximately 460–490 nm) [16]. Although the most effective light in vivo is most likely in the blue-to-green region [16,18], the described phototherapy is most effective in the blue emission spectrum, which is approximately 425–475 nm [19]. This finding suggests that blue light lamps are less detrimental to mammalian cells [20] and could be better and safer for phototherapy because blue light does not overlap with ultraviolet light-A. Although it is known that blue light can damage the eyes, controversial information exists regarding the influence of blue light in melanocytic nevus development [19,21]. Additionally, damage to mitochondrial DNA by blue light [22] has been demonstrated in cell culture [17].
Micronuclei are acentric fragments or whole chromosomes that are unable to migrate with the rest of the chromosomes during anaphase of cell division and are formed spontaneously or as the result of genotoxic agents. The in vivo micronucleus assay is a genotoxicity test that detects chromosome fractures (clastogenic agents) or mitotic apparatus malfunction (aneugenic agents) [1] and is performed in a wide variety of tissues, including peripheral blood [2,3].
In humans, micronuclei are removed from circulation primarily from the spleen [4,5]; however, in preterm newborns (PNBs), these structures can be observed in peripheral blood erythrocytes and can increase due to maternal diseases during pregnancy [6,7]. In previous studies, we observed that the number of micronuclei in circulating erythrocytes (MNE) is related to immune system maturity [3,6] and that MNE can be observed in immature states; as the organism matures, they are withdrawn from circulation, at which point their numbers should be close to zero [6,8]. This phenomenon also occurs in humans [6], and PNBs of less than 37 weeks of gestation and whose age is 0–7 days after gestation remain physiologically and metabolically immature [9]. In many species, the frequency of MNE in peripheral blood is increased at birth and diminishes as the spleen matures because these structures are removed more efficiently by the organism [5,6].
PNBs are exposed to diverse postnatal management procedures, such as parenteral nutrition, ventilator support systems, the use of central vascular catheters [10,11], or prolonged hospitalization and the use of surgical procedures; these postnatal management procedures could alter the number of MNE.’
—
The theory is thus as such: could the concentrated blue light being transmitted by LEDs of most electronic screens be affecting the blood vessels around the meibomian glands and leading to more inflammation, clogging of the meibomian glands’ orifices and leading to more gland atrophy
OR
Is it just the fact that patients blink less well that is causing this epidemic of meibomian gland dysfunction and atrophy leading to chronic eye pain syndromes at a rapid race?
Time and research will tell.
For now, I stick by my recommendation to only use your eyes for “Eye Worthy” things and blink frequently and fully and look away from the screen frequently….and as I am doing right now, type with your eyes closed from time to time!!
SLC
Reference:
1.
Journal of Photochemistry and Photobiology B: Biology
Volume 141, December 2014, Pages 283-287
Effects of blue light phototherapy on DNA integrity in preterm newborns
[Blue Light Warning] Do NOT Read This Page After Dark!
PLEASE SHARE WITH FAMILY AND FRIENDS:
You’re destroying your body right now without realizing it… and it’s all because of Thomas Edison. Sound crazy? It is. And it’s true… As you look at this screen, your death clock is speeding up. So, get informed NOW.
Are you reading this at night? Because, if you are…
STOP RIGHT THERE.
I’m not kidding. If it’s dark outside right now, bookmark this page and walk away. Come back and read it when it’s light out.
Why am I telling you to do this? The screen you’re looking at right now. That’s why.
This screen — whether it’s on a phone, a tablet, or a computer — is emitting a specific type of light called blue spectrum light.
And special receptors in your eyes are using this light as a signal to regulate your body’s internal processes — like sleep, wakefulness, immunity, blood sugar, and more…
The trouble is, thanks to screens like this one… you’re currently getting large doses of blue light at all the wrong times.
You see, until recently, the sun was your only source of blue light. So, for most of human existence, you only saw this light during the daytime.
That’s why your body evolved to use blue light as a guide for your internal health clock — also known as your circadian rhythm.
“Health clock” hormones like melatonin are controlled by your body’s exposure to blue light.
This rhythm determines when your body rests, repairs itself, craves food, and performs a number of other vital activities. I’m not exaggerating in the least when I say your life depends on the careful timing of all these processes.
And historically, sunlight was a very dependable way to set the timer. Unfortunately, this is no longer the case…
IN THE 21ST CENTURY, IT’S “DAYLIGHT” ALL THE TIME.
Starting just over a decade ago… social media and Internet videos began to take off. Touch-screen smartphones exploded in popularity. Touch-pad tablets and Kindles hit the market. And more people than ever before gained access to laptops and computers.
Along with 3.56 billion other people across the world… you’re looking at one of these devices right this very moment.
And after you close this device, you’ll probably use that flat-screen television in your living room… or maybe that touch-screen navigation system in your car. Perhaps you’ll even go to the gym… where you can hop on that fancy elliptical with the digital monitor attached to it.
And now, the BAD news: Light-emitting diodes (LEDs) — which illuminate the screens on ALL these devices — hit your eyes with a concentrated blast of blue light. 1
In other words, you’re currently looking straight into blue light sources at all hours of the day and night — including right this moment.
Your brain is getting bombarded by unprecedented amounts of blue light… at unnatural times.
And with all these blue light signals, your body can no longer regulate your internal health clock properly. What are the consequences of this? You’re about to find out.
Here’s a little preview: weight gain, depression, heart problems, metabolic problems, mental problems, constant fatigue, declining health…
But the first question I need to address is, “How does blue light exposure ruin your health?”
IT ALL STARTS WHEN YOUR DEEP SLEEPGETS DISRUPTED.
On more than one occasion, Ivy League researchers have shown that blue light exposure suppresses melatonin, making it harder for you to sleep. 2,3 But recent research shows that, even if you do manage to get to sleep… your sleep won’t be “deep” enough.
You see, NREM slow-wave sleep — or “deep sleep” — is how your body repairs the vital organs and systems that keep you alive and healthy. 4
These include your heart, lungs, brain, muscles, digestive tract, and immune system — in other words… all the things you spend your waking hours tearing up through heavy use.
And studies everywhere are now showing that nighttime blue light exposure disrupts your deep sleep patterns. One of these studies was recently conducted at the prestigious University of Basel in Europe.
In this study, 30 healthy adults were exposed to blue light for two hours before bed each night over the course of three months. Scientists discovered that, after the blue light exposure, the patients’ deep sleep patterns were bizarrely rearranged. 5
Shortly after the European sleep study was published… Harvard Medical School conducted their own sleep study right here in the United States.
In the Harvard study, doctors monitored the sleep of two separate groups of healthy adults for five consecutive nights. One group read a blue-light-emitting Kindle before bed each night. The other group read a printed book instead.
AND WHAT WAS THE RESULT?
The group who read the blue-light-emitting Kindle quickly started experiencing problems that might sound familiar to you: 6
- They took longer to get to sleep.
- They slept poorly.
- They were significantly more tired the next morning.
After the 5th night, the doctors running the study tried switching things up. They had the two groups trade reading methods and do another 5-night sleep cycle. The results were consistent: Whoever used the Kindle had the sleep problems. 7
Bottom Line: If you keep exposing yourself to blue light at night, your body will stop resting and recovering properly.
Blue light at night is altering your sleep patterns and damaging multiple systems in your body.
And once this change occurs, some nasty things start happening to you. Here are the Top 5 consequences of exposing yourself to artificial blue light at night…
1) YOU LOSE YOUR MENTAL SHARPNESS.
Without adequate deep sleep, your mental and physical abilities deteriorate. You probably already know this. But what you probably don’t know is how fast it happens…
The people exposed to blue light in the Harvard sleep study were noticeably more exhausted and “spaced out” within just a few days… even though they were still sleeping 7-8 hours per night. 8 Long-term, this gets worse — a LOT worse.
And the really sinister part is, as you get accustomed to being in this state… you stop noticing that you’re only running on 50% power! And even more alarming…
WHILE YOU’RE HAVING A HARD ENOUGH TIME JUST THINKING AND FUNCTIONING… YOU’RE HAVING AN EVEN HARDER TIME NOTEATING.
And this leads us to the second thing that happens to you:
2) YOUR APPETITE SKYROCKETS, AND YOU GET FAT.
You see, doctors now know that poor sleep increases ghrelin (the “hungry” hormone) and decreases leptin (the “full” hormone). In fact, Stanford University scientists were warning the medical community about this as early as 2004. 9
When blue light disrupts your sleep, your ghrelin and leptin go haywire — and you start eating like crazy.
IN OTHER WORDS, POOR SLEEP MAKES YOU FEEL HUNGRY ALL THE TIME.
And while you’re busy eating all that extra food… your body is busy storing most of it as FAT. This was proven in a landmark sleep and obesity study carried out on hundreds of adults over 6 years in Quebec.
When study participants didn’t sleep properly… their metabolism came to a screeching halt. 10
You can bet the same is true for you. And this “eat more, store more” cycle does more than just make the fat pile up on your body in record time. By slowing your metabolism, it also makes that fat nearly impossible to lose.
And, to add insult to injury, the weight you gain makes your sleep problems even worse.
Johns Hopkins researchers revealed this in a 2012 study, where they had 77 overweight people slim down to see if they slept better. Many different weight loss methods were used, but the result was always the same:
THE MORE BODY FAT PEOPLE LOST, THE BETTER THEY SLEPT. 11
And this eye-opening discovery revealed a disastrous loop your evening blue light exposure places you in:
NIGHTTIME BLUE LIGHT EXPOSURE RUINS YOUR SLEEP
POOR SLEEP FORCES YOUR BODY TO CRAVE MORE FOOD AND STORE MORE FAT
GETTING FAT GIVES YOU EVEN MORE SLEEP PROBLEMS
MORE SLEEP PROBLEMS MAKE YOU EVEN FATTER, AND SO ON
And by continuing to look at blue light at night… you’re accelerating this vicious, health-destroying cycle.
And as a cardiologist and heart surgeon, I can tell you right now — the long-term consequences of this aren’t pretty. You see, as you gain more weight and get less real rest…
3) AS BLUE LIGHT RUINS YOUR SLEEP PATTERN… YOUR BLOOD PRESSURE SHOOTS UP.
The blue-light-induced sleep problems you’re having — especially inadequate deep sleep — is wearing down the organs and systems that keep you alive. One of the worst-affected is your heart.
Without adequate deep sleep, your heart can’t repair itself properly.
You see, deep sleep is how your heart recovers from the previous day’s activity. When you start losing this vital section of your sleep cycle… your heart starts wearing down rapidly.
This was demonstrated in a groundbreaking study by doctors at UC San Diego and Harvard Medical School. In this study, 784 men were monitored for both sleep problems and heart problems over the span of 3 ½ years. At the end of the study…
THE DOCTORS DISCOVERED THAT DEEP SLEEP LOSS INCREASED THE CHANCES OF HYPERTENSION BY 80% IN JUST A FEW YEARS. 12
In other words… when blue light sabotages your deep sleep… your blood pressure cranks up and starts damaging your heart. And it’s not just your heart that’s getting damaged. When you get such poor sleep…
4) YOUR RISK FOR DIABETES INCREASES DRAMATICALLY.
You see, while adequate sleep is decreasing in the U.S.,13 diabetes is rapidly increasing.
In fact, according to a recent report from the CDC, diabetes is at an all-time high — virtually doubling since 1997. (Kind of interesting, since 1997 14 was around the time the Internet first started getting really popular.)
Diabetes is skyrocketing to an all-time high in the Digital Age. [Source: CDC]
The truth is, poor sleep and diabetes have been linked together in studies conducted at prestigious clinics all over the world. 15,16 And it didn’t take long for University of Chicago Medical School doctors to tie this directly to deep sleep. It turns out, deep sleep disruption messes up your body’s ability to regulate your blood sugar. 17
Remember how blue light was proven to screw up your deep sleep? The screen you’re looking at has been pushing your body toward diabetes for years.
So, you have cognitive problems, obesity, heart disease, and diabetes. That’s a pretty scary picture you’ve got. And I wish I could say it stops there… but we’re not done yet.
You see, this chain of events doesn’t stop at your physical and intellectual well-being. Your emotions go haywire, too… and your psychological decline gets very steep, very quickly. You see, as blue light wrecks your sleep patterns…
5) YOU PLUNGE HEAD FIRST INTO DEPRESSION.
The concept of sleep affecting your moods is nothing new. However, medical researchers are now discovering just how powerful and dangerous the connection is.
A massive sleep-depression study was recently conducted on 1,788 adult twins at the University of Washington Sleep Center. Their findings painted a clear picture, to put it mildly:
Poor sleep nearly doubled the participants’ risk for developing depression. 18
And new studies like this are coming out every year. The body of evidence is growing so rapidly, Dr. Lawrence J. Epstein at Harvard Medical School had this to say:
“People who have problems with sleep are at an increased risk for developing emotional disorders — anxiety and depression. There’s a very strong link.” ~ Dr. Lawrence J. Epstein, Harvard Medical School
NOW, LET’S PUT IT ALL TOGETHER…
To bring this all back to blue-light-emitting screens like the one you’re currently looking at… consider the following two facts:
1. Daily Internet “screen time” exploded between 2008 and 2012. 202. Prescriptions for heart, diabetes, and depression medications ramped up during the same period. 21
And as a cardiologist, I’ve had to write quite a few of those heart medicine prescriptions myself. I do NOT want to have to write one for you!
Chronic diseases are increasing alongside the use of blue light devices.
SO, WHAT CAN YOU DO ABOUT IT?
Alright, I know blue-light-emitting devices are unavoidable. And besides, your body is already designed to get blue light during the day. The main issue here is blue light at night. So, here are a few precautions you can take to minimize your nighttime blue light exposure:
1. IF YOU READ AT NIGHT, READ A REAL BOOK USING A REGULAR LIGHT.
In other words don’t use an Kindle or tablet. Save those for the daytime. And don’t use a fluorescent book light, as those put off a ton of blue light.
2. IF YOU HAVE TO USE A COMPUTER AT NIGHT, TRY BLUE-LIGHT-BLOCKING LENSES.
Studies show that blocking blue light with amber lenses improves both your sleep and mood. 22 So, if you must be on your cell phone, computer, or tablet late at night… these lenses are a good option.
And there are tons of brands — Uvex Skyper, Gamma Ray, Gunnar… The list goes on. Find a pair you like, and sleep easier! (I know I do.)
Blue-light-blocking lenses can help protect you from excessive blue light exposure at night.
3. STOP SPENDING YOUR WHOLE LIFE LOOKING AT SCREENS.
How many times did you reach for your cell phone while you read this article? (That is, assuming you’re not reading it on your cell phone.) How many hours a day do you look at a computer or tablet?
Looking at screens has become a widespread addiction. It’s a nervous habit we have when we don’t know what to do with ourselves. (I know I’m guilty of this.) Not to mention… it’s a major means of communication.
Well, I have a suggestion…
Go have a conversation with someone in real life. Half the times we’re buried in a phone screen… we’re ignoring someone right in front of us (who’s also probably buried in a phone screen).
Put your phone down. Get them to do the same. Ask them a question that throws them off guard. Get to know them better. Or call someone on your phone… it is a phone after all! Get a hold of someone you haven’t spoken to in a long time.
I promise you, doing this will make you feel better. It actually makes you feel like you’ve accomplished something with your day. Plus, you’re not looking at the blue light, and humans evolved to communicate with our voices.
That’s where our real humanity is!
If we all spent less time on our phones, laptops, and tablets… we’d all be much healthier and happier.
Life is out there in the world, not on this screen. So, I’ll tell you what… share this article with whomever you think needs to see it. Then, leave a comment telling me what you’re about to go out in the world and do… And then close this device and go do it!
Looking out for you (always),
Steven Gundry, MD
For more health news, keep reading:
7 HABITS FOR HEALTHY WEIGHT LOSS (ONE TIP MAY SURPRISE YOU!)
10 REASONS MEDITATION BENEFITS YOUR HEALTH
Sources:
1. Tosini G, Ferguson I, Tsubota K. Effects of blue light on the circadian system and eye physiology. Mol Vis. Jan 24, 2016; 22: 61-72. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734149/. Accessed January 16, 2017.
2. Gooley JJ, Chamberlain K, Smith KA, et al. Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans. J Clin Endocrinol Metab. Mar 2011; 96 (3): E463–E472. DOI: 10.1210/jc.2010-2098.
3. Lockley SW, Brainard GC, Czeisler CA. High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. J Clin Endocrinol Metab. Sep 2003; 88 (9):4502-5. DOI: 10.1210/jc.2003-030570.
4. Harvard Medical School Staff. The Biology of Sleep: Circadian Rhythms, Sleep Stages, and Sleep Architecture. HelpGuide Website, in Collaboration with Harvard Medical School. https://www.helpguide.org/harvard/biology-of-sleep-circadian-rhythms-sleep-stages.htm. Accessed January 17, 2017.
5. Chellappa SL, Steiner R, Oelhafen P, Lang D, Götz T, Krebs J, Cajochen C. Acute exposure to evening blue-enriched light impacts on human sleep. J Sleep Res. Oct 2013; 22 (5): 573-80. DOI: 10.1111/jsr.12050.
6. Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A. Jan 27, 2015; 112 (4): 1232-7. DOI: 10.1073/pnas.1418490112.
7. Id. at 1232-7.
8. Id. at 1232-7.
9. Taheri S, Lin L, Austin D, Young T, Mignot E. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med. Dec 2004; 1 (3): e62. DOI: 10.1371/journal.pmed.0010062.
10. Chaput JP, Després JP, Bouchard C, Tremblay A. The association between sleep duration and weight gain in adults: a 6-year prospective study from the Quebec Family Study. Sleep. Apr 2008; 31 (4): 517-23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2279744/. Accessed January 23, 2017.
11. Nam S, Stewart KJ, Dobrosielski DA. Abstract 10098: Predictors of Sleep Quality Improvement Among Overweight or Obese Individuals: A Randomized Controlled Trial. Circulation. Nov 20, 2012; 126 (Suppl 21): A10098. http://circ.ahajournals.org/content/126/Suppl_21/A10098. Accessed Jan 27, 2017. 12. Fung MM, Peters K, Redline S, Ziegler MG, Ancoli-Israel S, Barrett-Connor E, Stone KL; Osteoporotic Fractures in Men Research Group. Decreased slow wave sleep increases risk of developing hypertension in elderly men. Hypertension. Oct 2011; 58 (4): 596-603. DOI: 10.1161/HYPERTENSIONAHA.111.174409.
13. Knutson KL, Van Cauter E, Rathouz PJ, DeLeire T, Lauderdale DS. Trends in the prevalence of short sleepers in the USA: 1975-2006. Sleep. Jan 2010; 33 (1): 37-45. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802246/. Accessed Jan 30, 2017.
14. U.S. Centers for Disease Control. Early Release of Selected Estimates Based on Data From the National Health Interview Survey, January–September 2015: Diagnosed Diabetes. CDC Website. Feb 14, 2016. https://www.cdc.gov/nchs/data/nhis/earlyrelease/earlyrelease201602_14.pdf. Accessed Jan 28, 2017.
15. Larcher S, Benhamou PY, Pépin JL, Borel AL. Sleep habits and diabetes. Diabetes Metab. Sep 2015; 41 (4): 263-71. DOI: 10.1016/j.diabet.2014.12.004.
16. Knutson KL, Van Cauter E. Associations between sleep loss and increased risk of obesity and diabetes. Ann N Y Acad Sci. 2008; 1129: 287-304. DOI: 10.1196/annals.1417.033.
17. Tasali E, Leproult R, Ehrmann DA, Van Cauter E. Slow-wave sleep and the risk of type 2 diabetes in humans. Proc Natl Acad Sci U S A. Jan 22, 2008; 105 (3): 1044-9. DOI: 10.1073/pnas.0706446105.
18. Watson NF, Harden KP, Buchwald D, Vitiello MV, Pack AI, Strachan E, Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. Sleep. Feb 1, 2014; 37 (2): 351-8. DOI: 10.5665/sleep.3412.
19. Harvard Medical School. Sleep and Mood. Harvard Medical School Website. http://healthysleep.med.harvard.edu/need-sleep/whats-in-it-for-you/mood. Accessed January 30, 2017.
20. Meeker M. KPCB Internet Trends Report 2015. Kleiner, Perkins, Caufield, and Byers website. May 27, 2015. http://www.kpcb.com/blog/2015-internet-trends. Accessed Jan 30, 2017.
21. Kantor ED, Rehm CD, Haas JS, Chan AT, Giovannucci EL. Trends in Prescription Drug Use Among Adults in the United States From 1999-2012. JAMA. Nov 3, 2015; 314 (17): 1818-31. DOI: 10.1001/jama.2015.13766.
22. Burkhart K, Phelps JR. Amber lenses to block blue light and improve sleep: a randomized trial. Chronobiol Int. Dec 2009; 26 (8): 1602-12. DOI: 10.3109/07420520903523719.
2. Gooley JJ, Chamberlain K, Smith KA, et al. Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans. J Clin Endocrinol Metab. Mar 2011; 96 (3): E463–E472. DOI: 10.1210/jc.2010-2098.
3. Lockley SW, Brainard GC, Czeisler CA. High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. J Clin Endocrinol Metab. Sep 2003; 88 (9):4502-5. DOI: 10.1210/jc.2003-030570.
4. Harvard Medical School Staff. The Biology of Sleep: Circadian Rhythms, Sleep Stages, and Sleep Architecture. HelpGuide Website, in Collaboration with Harvard Medical School. https://www.helpguide.org/harvard/biology-of-sleep-circadian-rhythms-sleep-stages.htm. Accessed January 17, 2017.
5. Chellappa SL, Steiner R, Oelhafen P, Lang D, Götz T, Krebs J, Cajochen C. Acute exposure to evening blue-enriched light impacts on human sleep. J Sleep Res. Oct 2013; 22 (5): 573-80. DOI: 10.1111/jsr.12050.
6. Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A. Jan 27, 2015; 112 (4): 1232-7. DOI: 10.1073/pnas.1418490112.
7. Id. at 1232-7.
8. Id. at 1232-7.
9. Taheri S, Lin L, Austin D, Young T, Mignot E. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med. Dec 2004; 1 (3): e62. DOI: 10.1371/journal.pmed.0010062.
10. Chaput JP, Després JP, Bouchard C, Tremblay A. The association between sleep duration and weight gain in adults: a 6-year prospective study from the Quebec Family Study. Sleep. Apr 2008; 31 (4): 517-23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2279744/. Accessed January 23, 2017.
11. Nam S, Stewart KJ, Dobrosielski DA. Abstract 10098: Predictors of Sleep Quality Improvement Among Overweight or Obese Individuals: A Randomized Controlled Trial. Circulation. Nov 20, 2012; 126 (Suppl 21): A10098. http://circ.ahajournals.org/content/126/Suppl_21/A10098. Accessed Jan 27, 2017. 12. Fung MM, Peters K, Redline S, Ziegler MG, Ancoli-Israel S, Barrett-Connor E, Stone KL; Osteoporotic Fractures in Men Research Group. Decreased slow wave sleep increases risk of developing hypertension in elderly men. Hypertension. Oct 2011; 58 (4): 596-603. DOI: 10.1161/HYPERTENSIONAHA.111.174409.
13. Knutson KL, Van Cauter E, Rathouz PJ, DeLeire T, Lauderdale DS. Trends in the prevalence of short sleepers in the USA: 1975-2006. Sleep. Jan 2010; 33 (1): 37-45. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802246/. Accessed Jan 30, 2017.
14. U.S. Centers for Disease Control. Early Release of Selected Estimates Based on Data From the National Health Interview Survey, January–September 2015: Diagnosed Diabetes. CDC Website. Feb 14, 2016. https://www.cdc.gov/nchs/data/nhis/earlyrelease/earlyrelease201602_14.pdf. Accessed Jan 28, 2017.
15. Larcher S, Benhamou PY, Pépin JL, Borel AL. Sleep habits and diabetes. Diabetes Metab. Sep 2015; 41 (4): 263-71. DOI: 10.1016/j.diabet.2014.12.004.
16. Knutson KL, Van Cauter E. Associations between sleep loss and increased risk of obesity and diabetes. Ann N Y Acad Sci. 2008; 1129: 287-304. DOI: 10.1196/annals.1417.033.
17. Tasali E, Leproult R, Ehrmann DA, Van Cauter E. Slow-wave sleep and the risk of type 2 diabetes in humans. Proc Natl Acad Sci U S A. Jan 22, 2008; 105 (3): 1044-9. DOI: 10.1073/pnas.0706446105.
18. Watson NF, Harden KP, Buchwald D, Vitiello MV, Pack AI, Strachan E, Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. Sleep. Feb 1, 2014; 37 (2): 351-8. DOI: 10.5665/sleep.3412.
19. Harvard Medical School. Sleep and Mood. Harvard Medical School Website. http://healthysleep.med.harvard.edu/need-sleep/whats-in-it-for-you/mood. Accessed January 30, 2017.
20. Meeker M. KPCB Internet Trends Report 2015. Kleiner, Perkins, Caufield, and Byers website. May 27, 2015. http://www.kpcb.com/blog/2015-internet-trends. Accessed Jan 30, 2017.
21. Kantor ED, Rehm CD, Haas JS, Chan AT, Giovannucci EL. Trends in Prescription Drug Use Among Adults in the United States From 1999-2012. JAMA. Nov 3, 2015; 314 (17): 1818-31. DOI: 10.1001/jama.2015.13766.
22. Burkhart K, Phelps JR. Amber lenses to block blue light and improve sleep: a randomized trial. Chronobiol Int. Dec 2009; 26 (8): 1602-12. DOI: 10.3109/07420520903523719.