Lights emitted by smartphones eroding your sleep
Japan, says Shukan Asahi (Aug 17-24), is “an insomnia superpower.” That’s an unenviable distinction, as anyone who suffers sleep deprivation knows – and some 80% of Japanese do, experts say.
That’s not to say 80% of Japanese are full-blown insomniacs. Only 20% would qualify as that – a high proportion all the same. But 80% don’t sleep long or deeply enough, to the point that it adversely affects their daily lives. And it’s getting worse – owing, researchers are increasingly inclined to think, to increased use of smartphones. The blue light that smartphone screens emit just isn’t good for us, it seems.
The scientific explanation, courtesy of Kyorin University psychologist Yoshihiko Koga, is this: Blue light waves measure in at 380-495 nanometers (a nanometer is one billionth of a meter). That’s as short as visible light waves get. The shorter the wave, the higher the energy. Invisible ultra-violet light waves, shorter and more energetic, are known to age cells and cause eye damage.
The effects of blue light have yet to be pinned down with certainty, but the following test gives a clue: Participants used smartphones intensively an hour before bedtime, half of them wearing special spectacles that filter out half the blue light, the other half not. Then the sleep of all participants was assessed for quality and length. Those who had worn the spectacles slept on average 30 minutes longer than those who had not, and more of them said they woke up feeling refreshed physically and mentally.
Experts quoted by Shukan Asahi say evidence is growing that blue light damages eyesight over time. Especially vulnerable in this regard are children, whose eye lenses are more transparent than those of adults. “Children nowadays are exposed to LED liquid crystal screens from the time they’re very small,” says ophthalmologist Takeshi Iide. “There are concerns regarding the future effects on their eyes.”
To anyone old enough to remember a different time, it is astonishing to consider that between smartphones and personal computers, between work and personal use, an average company employee spends no less than 11 hours a day peering at a screen. Even if the scientific evidence linking this to increasing sleep disorders has not yet attained the level of certainty, it is at least, says Shukan Asahi, suggestive.
The magazine concludes with a checklist of 10 rules for sounder sleep, most of which we’ve heard before. Get up every day at a fixed time, have dinner three hours before bedtime, bath two hours before, shut down the computer and smartphone three hours before, learn to be satisfied with one beer with dinner, and so on in that vein.
It all makes perfect sense, except that such a calm and orderly withdrawal from the affairs of the world at the end of the day may not be possible in these feverish times of ours.