Results: Blue light isn't the only reason why bedtime screen time is a bad idea

Over half of Americans spend time on their phones within an hour of going to sleep, according to a survey by the National Sleep Foundation. That's the very latest we should shut off devices, experts say. Do you usually spend time on your phone within an hour of going to sleep?

"There are a million and one ways screens create problems with sleep," said Lisa Strauss, a licensed psychologist specializing in cognitive behavioral treatment of sleep disorders. The brain, she said, processes electric light — not just a smartphone's much-maligned blue light — as sunshine. That suppresses melatonin production, delaying deep sleep. Even very little bright-light exposure in bed has an impact. If you do use your phone before going to sleep, do you think it negatively affects your sleep?

Of course, doomscrolling through the news, checking emails or being tempted by ever more tailored videos on social media has its own consequences. So-called "technostress" amps you up — possibly even triggering the brain's flight or flight response. And algorithms designed to be engaging compel many social media users to scroll longer than they intended. Now it's 30 minutes later, when you wanted to watch a couple videos and fall asleep. If you use your phone before bed, do you find that you use it for longer than you anticipated?