TV is OK. Cell phones aren’t. Here is where you’re messing up your circadian rhythm

In an eye-opening segment, CNN’s Randi Kaye visits the University of Michigan’s Sleep Disorders Center to crack the case on why so many of us feel drained, even after a full night in bed. The culprit? A silent saboteur: our phones. While TV might seem like the usual suspect, neurologist Dr. Cathy Goldstein explains it's actually our handheld screens, with their up-close, blue-light glow, that wreak havoc on the brain’s melatonin release, disturbing the sleep-wake rhythm known as the circadian clock. The body is wired to respond to light.

But thanks to late-night TikToks and doomscrolling in bed, that light tells your brain it's still daytime, delaying sleep and muddying the quality of rest. “It’s not just when you sleep,” says Dr. Goldstein. “It’s about how your body prepares for sleep — and phones disrupt that signal.” So, what’s the fix? Start simple: dim the lights 90 minutes before bed, swap Instagram for a paperback, and don’t sleep with your phone in arm’s reach. It’s a plot twist most of us didn’t see coming — but your circadian rhythm will thank you.