Good Night, Blue Light


If you are one of the 50 to 70 million U.S. adults Americans who is sleep deprived, you’ve probably heard that the glowing blue light of your computer/tablet/phone is to blame.

Many studies indicate that exposure to bright blue light in the evening impacts your circadian rhythms – the biological cycle that regulates basic body functions. The circadian cycle synchs cycles such as sleep to a number of clues in the physical world. Blue light – think bright blue skies at noon – is a clue that its daytime. When exposed to blue light our bodies suppress the production of a natural hormone, melatonin, that makes us sleepy.

So it seems logical that something as simple as filtering out blue light could help you get a good night’s sleep. In response, device manufacturers and app developers have been working hard to figure out a solution for enabling people to use their little electronic friends without losing sleep. But there’s no firm evidence that Blue Light filters are the cure-all for sleep problems.

Night Shift

Apple’s Night Shift feature in iOS 9.3 lets you adjust the color temperature of your device’s display, shifting away from blue light spectrums.

Apple makes no promises on the sedative effect of Night Shift, saying only that the feature “may help you get a better night’s sleep.” Science supports that idea, but when you dig into the data you don’t find computer/device displays – no matter how sizable – mentioned as a source of sleep-wrecking illumination.

MacWorld’s Glenn Fleishman figures that “Night Shift also can’t remove enough blue to make a difference if that color is the culprit … (Night Shift provides) at best a placebo effect and a reminder to power yourself down.

Apple might have done better to create something called Night Safe, an option that would countdown the moments until you’d be locked out of your hardware till morning except for emergencies or going through a tedious override process—a Do Not Disturb on reverse steroids,” Fleishman adds.

Apple isn’t the only company offering a blue light filter. Android has Night Mode (android 6,0), which can automatically adjust a device’s display from bright white to dark according to the time of day, and includes a blue light filter that can be activated independently.  And there are apps for both platforms that provide blue light filtering, either for the specific app (such as Moon Reader’s ereader app) or system-wide, such as f.lux software – which makes your device’s display mimic the lighting of the room that you are in.

Dimming displays can be soothing. But it is quite possible that the actual activities we’re performing while gazing at our device’s displays are really to blame for keeping us up late. Reading a great eBook, playing games, socializing, may be stimulating the brain rather than letting it wind down. Or it may be a combo of activity and blue light that is making so many of us zombies.

Two Hours To Sleep

As noted above, our bodies suppress melatonin production when exposed to bright light. About two hours before your body’s natural sleep cycle begins (scientists figure that for most of us, that’s 10PM local time) melatonin production ramps up and then peaks during the early hours of the morning.

Mariana G. Figueiro, a professor at Rensselaer Polytechnic Institute and the program director of its Lighting Research Center, told CNN Money that “The idea (of blue light filtering) is good, but it is not just about color. The intensity matters too, so color needs to be shifted and intensity needs to be dropped. But these options are better than nothing.”

Some research indicates that turning down a device’s blue light to a level that is sufficient enough to really make a difference in our ability to sleep would result in an unusable display.

Ray Soneira, the president of DisplayMate, a company that makes video-diagnostic hardware and software, says that “In the case of Night Shift and similar systems … the blue component would need to be entirely removed or reduced significantly more than the systems offer, which in turn would make the display too yellow for most people. He writes, “Just slightly reducing the blue, which is what most apps do, won’t accomplish much, so the improvements people experience are often mostly due to placebo and their own conscious modification of their behavior in using displays.”

If what may be a placebo effect helps you to get to sleep, go for it.  Chronic sleep deprivation can result in a decrease of your ability to learn, remember and think. You are likely to be cranky, notice your attention span is short, and find that your reflexes are slowed. People who sleep less than five hours a night have a 15% greater risk of death from all causes than people who get a good night’s sleep. So turn off (or tune down) the light, start counting sheep, and get yourself some sleep.


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