The Light from Your Partner’s Screen Is Screwing Up Your Sleep

Even if you really love your iPhone, you probably shouldn’t be spooning with it in bed because its blue light suppresses the natural production of melatonin, making it that much harder for you to sleep. All of which can leave your circadian rhythm moving to the beat of an old white guy biting his lip on the dance floor, and ultimately hinder your mental and physical health. 

The thing is, you might have to kick your partner out of bed along with your phone, because new research indicates that the light from their device could be powerful enough to keep you up all night, too — even if your eyes are closed.

This finding is courtesy of Hideki Sakai, a professor at Osaka Metropolitan University in Japan, who put 33 study participants under bright monochromatic red, yellow, green, blue and white LED lights that covered their entire face. Then Sakai made adjustments to the level of brightness and color and measured the responsiveness — both with his subjects’ eyes open and closed. 

The results revealed that the amount of light transmitted through the eyelid was about 10 times higher than what researchers had previously reported. And for some people, there was almost no difference between when their eyes were open or closed. “By properly understanding and utilizing the lighting environment when the eyes are closed, I hope to advance research on appropriate lighting not only during normal sleep but also in various other situations, such as during naps or riding late-night transportation,” Sakai explained in a press release. “Since light colors with low transmittance are perceived as dark only when people close their eyes, I think that this finding could be useful for designing lighting in spaces with both awake and sleeping people, such as evacuation centers.”

In other words, if you happen to be sleeping next to a night owl, it’s best to help them see the light — by having them shut theirs off.