According to the CDC, insufficient sleep is a national epidemic, “linked to motor vehicle crashes, industrial disasters, and medical and other occupational errors.”(1)
While there are many factors that contribute to people not getting enough sleep, the CDC also estimates that “sleep insufficiency may be caused by broad scale societal factors such as round-the-clock access to technology”.
Now there’s evidence that a certain factor of technology is to blame in particular – blue light from computer screens and other electronic devices can mess with our circadian rhythms.
A Case Of The Blues
Light has the ability to suppress the onset of melatonin, the “sleep hormone”, and shorten the melatonin duration in humans(2), making a good night’s sleep difficult.
But blue light is particularly insidious threat to our circadian rhythms, although it can have a positive effect on other aspects of human health.
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“Researchers have shown in humans that light influences hormone secretion, heart rate, alertness, sleep propensity, body temperature, and gene expression. Moreover, in such studies, blue wavelengths have been found to exert more powerful effects than green wavelengths… The blue wavelength suppress(es) melatonin for about twice as long as the green… blue also proved more powerful in elevating body temperature and heart rate,” writes David C. Holzman, a writer for the Smithsonian and the Atlantic Monthly(3).
Blue light is used to treat neonatal jaundice, jet lag, and seasonal affective disorder, but when it comes to bedtime, it’s best avoided due to its melatonin-suppressing effects.
So how do you cut down on your exposure to blue light around bedtime?
Not Quite Rose-Colored Glasses
The answer for some seems to be in yellow-tinted sunglasses, which can filter out blue light and keep it from being processed by your brain.
In two separate studies, the effects of amber sunglasses on sleep habits were put to the test. The first study looked at “blue-blocker” glasses and the effects that they had on the sleep habits of night shift workers, who typically complain about disturbed sleep during the day.
“When wearing the glasses, workers slept, on average… more minutes (per) day, increased their sleep efficacy… and lowered their sleep fragmentation,” the authors concluded. “Blue-blockers seem to improve daytime sleep of permanent night-shift workers.”(4)
The second study, a randomized trial, had participants complete sleep diaries during a one-week baseline assessment, followed by two weeks’ use of amber-tinted glasses before bed.
“At the end of the study, the amber lens group experienced significant improvement in sleep quality relative to the control group… mood also improved significantly relative to controls.”(5)
Improving Your Health By Improving Your Sleep
According to Harvard University, exposure to light – especially blue light – at night is related to several types of cancer, as well as heart disease, diabetes, and obesity.
“It’s not exactly clear why nighttime light exposure seems to be so bad for us. But we do know that exposure to light suppresses the secretion of melatonin… and there’s some experimental evidence (it’s very preliminary) that lower melatonin levels might explain the association with cancer,” one researcher writes(6).
Clearly, getting a good night’s sleep isn’t just a matter of feeling more alert the next day.
How can you cut down on your nighttime exposure to blue light and get better sleep? Here are some tips:
1. Invest in a pair of amber-tinted glasses designed to filter out blue light.
2. Limit your exposure to computers, television, and other electronic devices before bed – avoid looking at bright screens for at least two or three hours before heading to bed.
3. Expose yourself to bright light, especially sunlight if possible, during the day. This will boost your mood, as well as your ability to sleep at night.
4. Finally, try using dim red lights for night lights. Red light is the least disruptive when it comes to the production of melatonin.