Whether you're texting sweet nothings to your significant other or compulsively refreshing your Instagram feed before bed, chances are you usually fall asleep with your glowing phone right next to your face.
You probably already heard that it's not good for you — but you had no idea why. Well, now we know why: It disrupts our circadian rhythms, the light-triggered releases of hormones that enable restful sleep.
New findings published in the British journal Philosophical Transactions of the Royal Society B show us that the fact that we aren't adequately exposed to natural light during the day and then overexposed to artificial light at night can actually mess up our circadian rhythm.
And circadian disruption has in turn been linked to a host of health problems, such as cancer, diabetes, obesity, and depression.
"It's become clear that typical lighting is affecting our physiology," said lead author Richard Stevens, in a news release. "But lighting can be improved. We're learning that better lighting can reduce these physiological effects. By that we mean dimmer and longer wavelengths in the evening, and avoiding the bright blue of e-readers, tablets and smart phones."
Their analysis found that the devices we've grown so accustomed to emit enough blue light to actually disrupt our body's natural clock when used in the evening.
"We don't know for certain, but there's growing evidence that the long-term implications of this have ties to breast cancer, obesity, diabetes, and depression, and possibly other cancers," said Stevens, though, as always, it's important to remember that correlation doesn't necessarily mean causation.
But according to Stevens, most people live in a sort of "circadian fog." So while the extent to which health risk can be attributed to artificial light is still unclear, it's probably a good idea to break out of that fog while more research is being done.
If you have a choice between an e-reader and a book, at night, choose the book. And maybe get in the habit of texting goodnight to your boo well before you get into bed.