It may seem harmless to veg in front of the TV before bed. You tune in, relax, zone out, and, eventually, you nod off. Plenty of people do it—as many as two-thirds of adults worldwide. But if your goal is to get a good night’s sleep, your best bet is to turn off the tube.
One problem with bedtime TV watching is simply the temptation to stay up late to find out what happens next. Plus, violence, gore, or suspense may leave you feeling anxious and could contribute to tossing and turning. But neither of these is actually the main concern.
The biggest problem is that the bright light that your TV screen emits may actually keep you up. In a natural world, your body clock is set according to the rise and fall of the sun. In the evening, you start to produce a hormone called melatonin that gradually makes you feel sleepy. It continues to increase over the course of the night, helping you to fall asleep and stay asleep until morning. But it dissipates in the wee hours, and is ultimately snuffed out by dawn’s light.
Enter: artificial lights. The mere existence of electricity has allowed you to move away from your reliance on nature to tell you when it’s time to be awake and when it’s time to sleep. The increasing use of screens, including televisions, computers, tablets, and smartphones is especially problematic for sleep. That’s because electronics emit a particular type of blue light that is capable of triggering the brain to stop making melatonin.
Even if your eyelids start to droop while you watch TV, you’re not immune. You might feel like you can fall asleep just fine after your show wraps up, but your sleep can still be affected. The blue light exposure can delay the onset of REM sleep and lead to morning drowsiness. In other words, even if you think that you’re sleeping fine, you might not be getting the quality sleep that you need.
For the best night’s sleep, consider pretending that you live in an earlier time. Wind down by reading a (paper) book, writing in a journal, or chatting with your partner. And if you can’t bring yourself to miss your favorite shows, consider using technology to help: Record your favorite show and watch it the following night—but an hour earlier than usual—so you can unplug and prepare for a good night’s sleep.