Gadget-addicted Swedes claim it’s now safe to read off of smartphone in bed
The study published in the scientific journal “Sleep Medicine” might be a relief for those who worried that bedtime reading off of electronic devices can disturb one’s sleep patterns and bring harm to one’s health. It might be a relief, however, if you only read every other word.
The finding suggests that “two hours of evening reading on a self-luminous tablet […] does not alter sleep,” but only in the case of “daytime bright light exposure.”
Neuroscientists at Uppsala University say they surveyed 14 young men and women, first exposing them to bright light for hours during the afternoon and then asking them to read for two hours in the evening. One half of the group was reading off of a tablet, and the other half off of a paper book. In the morning following evening reading, all participants were asked about the time it took for them to fall asleep, how well they had slept, and how well rested they felt. After comparing the results for two weeks, researchers discovered that the two groups' levels of melatonin (hormone affecting human sleep-wake cycle), was the same for both gadget-users and old-fashioned readers.
“Melatonin is sensitive to light, and bright light during the day helps suppress its production and release. That is to say, if you expose yourself to bright light during the day, your brain exhibits a strong drive to produce and release melatonin during evening hours,” the study concludes, adding that bright light exposure actually eliminates the undesirable effects of light-emitting electronic devices on sleep.
So, what the Uppsala team says, is that no matter what you read before bedtime, you’ll fall asleep just fine if you soak in bright sunlight the entire day (Pokemon Go lovers would probably rejoice at the news). Apparently, if you toil your day away in an office without sunlight, or if it's, say, winter, you're out of luck.