Electric lighting is a major culprit in our chronic state of sleep deprivation, according to a new perspective published in the journal Nature.


Dr. Charles A. Czeisler, M.D., Ph.D., a professor of sleep medicine at Harvard Medical School, makes the case that electric lighting can seriously affect our natural sleep cycles. He explained in the perspective that just like our ears are important for both hearing and balance, our eyes also have two purposes -- vision and influence over our circadian clocks, because of our intrinsically photosensitive retinal ganglion cells that are sensitive to light.


When our eyes are exposed to artificial light, it stops sleep promoting neurons and activates arousing neurons, leading us to feel less sleepy, he explained.


"Technology has effectively decoupled us from the natural 24-hour day to which our bodies evolved, driving us to go to bed later," Czeisler wrote in the perspective. "And we use caffeine in the morning to rise as early as we ever did, putting the squeeze on sleep."


Czeisler also draws correlations between the decreases in the cost to produce artificial light and the increases in usage of that artificial light.


"Between 1950 and 2000, for example, as the cost of light production fell sixfold, UK per capita light consumption rose fourfold. This increasing light consumption has paralleled the rise in sleep deficiency," he wrote.


He also points out that light-related sleep problems may only get worse, because LED lighting is increasingly replacing incandescent light bulbs. This makes a difference to sleep because laptops, tablets and phones all use LED lighting -- which "will drive a further increase in per capita light consumption," he wrote.


Plus, LED lights are particularly bad for our sleep because the intrinsically photosensitive retinal ganglion cells in our eyes respond more to blue and blue-green lights -- like the ones typically emitted by LEDs -- thereby interfering with sleep through melatonin disruption. However, he also noted that it's possible to change the color composition of LED lighting, so that the intrinsically photosensitive retinal ganglion cells in our eyes won't be as sensitive to it.


Sleep doctors have been telling us all along that good sleep hygiene involves unplugging before bed. HuffPost blogger Dr. Michael J. Breus points out in this blog post that not only does artificial light suppress melatonin, using technology before bed makes the brain active (making it harder to fall asleep) and also "brings the rest of your life into the bedroom, and as I've said before, the bedroom should be a sanctuary reserved for sleep."


Earlier this year, a study in the journal Pediatrics showed that kids who watch TV before bed end up going to bed later than their peers who stayed screentime-free before sleeping.


And in 2011, the National Sleep Foundation conducted a survey showing that technology is a huge culprit in robbing Americans' sleep.


Also on HuffPost:






  • Lullabies


    Soothing music before bedtime can really do the trick. A 2005 study found that older people who listened to 45 minutes of soft tunes before hitting the hay reported a <a href="http://www.blackwellpublishing.com/nursing/news/news.asp?id=124" target="_hplink">35 percent improvement in their sleep problems</a>.

    But it doesn't have to be Brahms, if that's not your style. As long as the music was soft and slow -- around 60 to 80 beats per minute -- it can spur <a href="http://news.bbc.co.uk/2/hi/health/4228707.stm" target="_hplink">physical changes known to promote sleep</a>, like a slower heart rate and breathing, the BBC reported.

    "We know that when a person closes their eyes they induce a certain frequency of brain waves," says Decker. Slow music may have a similar effect, he surmises, leading to sleep onset.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/llimaorosa/112246369/" target="_hplink">Llima</a></em>




  • Warm Milk


    It was once thought that a glass of warm milk at bedtime would help send you off to dreamland because of the tryptophan, <em>The New York Times</em> reported, but milk and other protein-rich foods actually <a href="http://www.nytimes.com/2007/09/04/health/04real.html" target="_hplink">block tryptophan's sleepiness-inducing effects</a>. However, there might still be a psychological benefit to that warm milk, the <em>Times</em> concluded, calling it "as soothing as a favorite old blanket."

    "There have been some studies showing that when infants receive warm milk before bed, they'll dream a little bit more," says Decker, but the results don't hold true in adults. "It may be one of those myths that because it happens in children, adults think it may be true for them, too," he explains. However, many adults are actually at least slightly lactose intolerant, he says, meaning a warm mlik at bedtime may just lead to discomfort.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/julianrod/152930252/" target="_hplink">julianrod</a></em>




  • Counting Sheep


    If your goal is to bore yourself to sleep, you might try counting sheep, or counting backwards by multiples of three or any of a number of other counting-related mind-numbers. But a 2002 study found that <a href="http://www.ncbi.nlm.nih.gov/pubmed/11863237" target="_hplink">imagining a more relaxing scene might be more effective</a>.

    The study observed 41 people with insomnia over a number of nights and asked them to try a variety of different sleep-inducing techniques, like counting sheep.

    On the nights they were told to imagine relaxing scenes like a beach, a massage or a walk in the woods, <a href="http://www.mentalfloss.com/blogs/archives/53137" target="_hplink">they fell asleep an average of 20 minutes sooner</a> than on the nights they were told to count sheep or were given no instructions, Mental Floss reported.

    Decker agrees. "Counting sheep in and of itself may not help," but can act as a ritual that prepares us for sleep, making it not unlike meditation. Counting sheep -- or more relaxing guided imagery -- helps us "focus on something other than life's stressors," he says. "Thinking about a soothing environment may be more restful than the way you spent the last eight hours!"

    <em>Flickr photo by <a href="http://www.flickr.com/photos/narciss/3716241331/" target="_hplink">Kr. B.</a></em>




  • Breathing Exercises


    Focusing on the breath, whether it's as part of a pre-bed yoga sequence or just a tuned-in awareness, can also have meditation-like effects in preparing for bed, says Decker, like lowering the heart rate.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/perfectoinsecto/2363255713/" target="_hplink">Perfecto Insecto</a></em>




  • Warm Bath


    Your body temp <a href="http://www.health.com/health/condition-article/0,,20189095,00.html" target="_hplink">dips about two hours before bedtime</a>, <em>Health </em>magazine reported, a natural change that "triggers our brain for sleep onset", says Decker. Soaking in a warm bath beforehand boosts your temperature temporarily, but results in a dramatic, rapid cooldown after you get out that relaxes you and eases you into sleep.

    It's not necessarily the bath that lulls you to sleep, it's that resulting cooling of your body temperature, Decker emphasizes. Research shows that people who take a warm bath before bed not only <a href="http://www.ncbi.nlm.nih.gov/pubmed/2578367" target="_hplink">fall asleep more quickly</a>, but also report better quality of sleep, he says.




  • Alcohol


    Many people swear by a drink to unwind at the end of the day, but alcohol before bed can actually <a href="http://www.huffingtonpost.com/2012/07/04/fourth-of-july-sleep_n_1644627.html#slide=1176662" target="_hplink">disrupt your sleep</a>. You'll be more likely to wake up more often in the early-morning hours, wake up and not be to fall back to sleep or have disturbing dreams. "As alcohol is metabolized by the liver, it has a disruptive effect," says Decker. It takes a few hours to metabolize, he says, so a drink with dinner shouldn't be a problem, but anything too close to bedtime can be counterproductive.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/rob-qld/2889139445/" target="_hplink">Rob Qld</a></em>




  • Get Out Of Bed


    It sounds crazy -- how will you ever get to sleep if you're not even in bed?! -- but it works, says Decker.

    "When a person stays in bed and they can't sleep, the bedroom can induce a certain level of anxiety," he says. "We say after 15 or 20 minutes, get out of bed, sit in another part of the house until you feel a little groggy, then go back to sleep," he says. "Staying in bed can condition you to become anxious in bed."

    A small 2011 study published in the <em>Archives of Internal Medicine</em> found that among the <a href="http://healthland.time.com/2011/01/27/cant-sleep-it-may-help-to-get-out-of-bed/" target="_hplink">adults studied who reported trouble sleeping</a>, those who spent <a href="http://www.thirdage.com/news/insomnia-cant-sleep-get-out-bed_1-26-2011 " target="_hplink">less time in bed had better sleeping habits</a>.

    <em>Flickr photo by <a href="http://www.flickr.com/photos/perfectoinsecto/3948115802/" target="_hplink">Perfecto Insecto</a></em>




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