What the science really says about falling asleep as the sights and sounds of your favorite show wash over you.
Nearly every day for the past, say, five years, I've fallen asleep in much the same way. I lay down, put my computer next to my head, pull up a random episode of The Simpsons that I've seen maybe several dozen times, and hit play. I dim the screen's brightness, roll away from the computer, and listen to my favorite fictional family do … something. Usually, I have no idea, because I'm often asleep before the end of the theme song.
Watching—or listening, more accurately—to TV is the most reliable way for me to fall asleep. And yet, self help websites, marginally researched articles in popular health magazines, and websites run by sleep experts who also happen to sell "blue light" filters tells me that falling asleep with a computer next to my face is one of the worst possible things I can do. But is falling asleep with the TV on actually bad for you?
The answer to this question is immensely important. A 2011 study commissioned by the National Sleep Foundation found that 95 percent of Americans use some sort of electronic device within an hour of falling asleep at least once a week; 60 percent of Americans watch TV immediately before going to sleep "every night" or "almost every night." Huge numbers of people are watching TV as they fall asleep, yet not everyone is a walking zombie the next day. What gives?
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Nearly every article telling you to not fall asleep with the TV (or your smartphone, or your laptop) on references one of a couple studies about the effect of blue LED light—a wavelength of light that comes out of most of our electronic devices—on melatonin, a hormone that regulates your circadian rhythm. The theory is that blue light inhibits the production of melatonin, which tells your body that it's time to sleep. An out-of-whack circadian rhythm can make it harder to fall asleep, make you more alert before bedtime, and prevent you from entering deeper stages of sleep.
"Normally melatonin is secreted right around bedtime, when people would go to sleep, it begins to secrete and it peaks when you get to sleep," Stuart Quan, a Harvard Medicine physician in the sleep and circadian disorders section of Brigham and Women's Hospital, told me. "Right in that time frame, if you tend to try to fall asleep and you're exposed to light and especially blue light, it will tend to inhibit the production of melatonin and your ability to sleep."
One of the most commonly cited studies, done by researchers at the University of Toronto, found that wearing goggles that filtered out blue light lessened sleep disruption in people who worked the night shift. Two separate Harvard studies have also shown that blue light suppresses melatonin more than other types of light.
Millions upon millions of people fall asleep with the television on every night, so it seems crazy that there haven't been more specific studies into how it affects us
But none of these studies is particularly large, and all of them focus very specifically on the effects of light on circadian rhythm, not the effects of television on sleep. One of the Harvard studies had a study size of 10 people and used different wavelengths of light as its variable; the other had a study size of 12 people and used backlit ereaders vs nonbacklit ones. The University of Toronto study followed 36 full-time nurses and also focused on light. Still, the results of those studies have been so convincing that many in the field say the science is settled.
"It's certainly accepted science at this point that blue light changes the circadian rhythm," Quan said. "But there's some inherent differences among people and their sleepiness and how they develop and grow up into different sleep routines. Sometimes these routines are sufficiently strong enough that they override deleterious effects of light exposure."
The findings of these studies (and the press releases and quotes given by the scientists involved in them) have been enough for hundreds of publications to—rightly or wrongly—make the connection that TV is definitely bad for sleep. The story isn't that simple, however.
No inpatient sleep studies that I could find or that Quan has heard of have looked specifically at the relationship between sleep quality and watching TV before bed.
There have been a smattering of studies that have associated having a television in the bedroom with nightmares in young children, and a few studies that look at television viewing during certain times of the night and attempt to associate it with sleep quality (this one found that using the internet was disruptive when compared to watching TV), but none have actually looked at what's going on in the brain or whether it might help certain people fall asleep.
"There have been studies about alcohol and drug use that look at sleep quality. I haven't seen anything about television," Quan said. "Most of the studies look at whether you're exposed to the light or not, but not what you're actually doing."
Watching television is one of the few inherently passive activities we can do. Letting the stimuli wash over you is inherently different than activities that more actively stimulate the brain and the body such as reading or playing a game on your cell phone.
Millions upon millions of people fall asleep with the television on every night, so it seems crazy that there haven't been more specific studies into how it affects us. Michael Breus, who calls himself the "Sleep Doctor" and works with insomnia patients, says the specific relationship between watching television before bed and sleep quality is a huge hole in the medical literature.
"Let's be honest. There's a large percentage of population that sleeps with the television on and it's not that hard to figure that statistic out," he added. "We should try to understand if it's a health hazard or, maybe, even if it's a positive."
"It's funny, you're at least the 10th person to tell me they watch The Simpsons or Seinfeld to fall asleep"
Breus said it's unclear who would pay for such a study, however. Inpatient sleep studies are expensive (hence the small sample sizes of the studies I referenced above), and the idea that television is bad for sleep quality isn't a terribly controversial one. He said it may be in the interest of a big network or a company like Netflix to sponsor one, but whenever corporate money starts sponsoring science, things like scientific independence come into play.
And so we can only make anecdotal, educated guesses about television's impact on our sleep. The first thing worth thinking about is why are people watching TV in bed? There's a body of research suggesting that constant notifications in an increasingly connected world are making us more frenetic, more stressed, more anxious. Those notifications are also making us more distracted. So when you lay down to sleep, all the things that you shrugged off during the day come rushing back and keep you awake. Anxiety is one helluva way to keep you awake at night, Breus says.
"In my insomnia practice, 40-50 percent of patients require a distraction to fall asleep," he said. "You get in bed, turn off light, and it's quiet. All the thoughts come rushing back in. "There's a thing called autonomic arousal—things like heart rate, anxiety, muscle tension—they rise as you think about a stressful thing. You can't enter into unconscious sleep while those are at an elevated level. Watching TV is a passive activity, you let the stimuli float over you and eventually, you're asleep."
Breus said that common wisdom has suggested falling asleep with the TV on is bad, and it's been repeated ad nauseum.
"I talked to Peter Hauri, who coined the term 'sleep hygiene,' and told him I have a lot of patients who fall asleep with the TV on," Breus told me. "He said, 'Look, general recommendations are for the general public. People who can't fall asleep aren't part of the general population and should do what works for them.'" (Hauri died in 2013, so I couldn't get his thoughts on the subject.)
Watching TV before going to sleep may not be good for you, but it may be better for the alternative. The science is also lacking on what the "safest" way to fall asleep watching TV is, though we can make some more educated guesses: A TV across the room is probably less likely to keep you awake than a Netflix-playing laptop that's next to your face; dimmer screens are probably better than brighter ones; facing away from the TV and simply listening to the sound is probably less stimulating than actually watching the TV (there's evidence that music actually improves sleep—is it possible the sound from TV does, too?); comedies or C-SPAN are probably better to watch than Breaking Bad or anything scary or dramatic; reruns you've seen are probably better than new shows.
"I'm the only sleep specialist I know of who says it's OK to fall asleep with the television on," Breus told me. "People have a pretty good understanding of the level of sleep they got—from an objective standpoint, falling asleep with the TV on might not be the best, but if you're waking up and feeling refreshed, without aches and pains, those are the measures that matter."
I told Breus that, overall, I feel like I sleep OK, even though I sometimes end up dreaming about The Simpsons.
"It's funny, you're at least the 10th person to tell me they watch The Simpsons or Seinfeld to fall asleep," he said. "That's perfectly fine. It's fine."
You'll Sleep When You're Dead is Motherboard's exploration of the future of sleep. Read more stories.