We don’t get enough sleep.

Chances are good that you know this first hand, and if that’s the case you’re in good company. So many of us are not getting enough Zzzs that the Centers for Disease Control and Prevention declared insufficient sleep a public health epidemic, linking it to car crashes, medical errors, and diseases as varied as diabetes, depression, and obesity.

The CDC isn’t the only one who’s noticed that we’re too tired; companies have produced a slew of products to improve our sleep. They’ve researched and redesigned mattresses, opened sleep spas in airports and offices, and created an array of sleep apps. The last of these is a particularly ironic development because technology ruined our sleep long before it set out to improve it.

Opening Our Eyes

Communication Studies Professor Jan Van den Bulck has spent much of the last decade trying to figure out how cell phones and tablets are shrinking our dream time.

It’s a tricky field to research, Van den Bulck explains, because “technology evolves so rapidly that the academic and the public health worlds have a hard time keeping up.” New devices are released so quickly that a study’s findings can be outdated as soon as the study is done.

Research may need to work to remain relevant, but there has been enough of it to link electronic devices to inadequate sleep and to generate some theories that might explain why. Some researchers believe the devices’ “blue light,” also known as short-wavelength enriched light, interrupts the body’s circadian rhythms by tricking the brain into producing less melatonin, Van den Bulck says.

According to one industry estimate, by 2017 over a third of the world’s population is projected to own a smartphone, a total of almost 2.6 billion smartphone users worldwide.

Another theory, sleep displacement, describes the situation in which a person browses the web or binge watches TV shows instead of going to sleep. Van den Bulck notes this behavior has a stronger effect on children and teens who have less control over what time they must wake up and leave to go to school. “As adults,” he says, “we get to adjust our schedules. If we want to stay up and watch a movie, we can also decide to sleep in a little later.” Kids don’t have a choice.

Kids are also especially vulnerable to another sleep-interrupting behavior Van den Bulck has studied extensively: texting. Van den Bulck’s research has found that more than half of teens admit to texting their friends after bedtime, which, of course, delays when they fall asleep. But kids who leave their phones on while they sleep also receive text messages, which also disrupts their slumber. Van den Bulck’s research indicates that teens who use their phones after going to bed even once per week are three times more likely to report they feel very tired than teens who don’t, and to continue to report feeling very tired a year later. Van den Bulck believes the effect of having phones in teens’ bedrooms goes even further. 

Adults are not immune to the urge to reach out right around bedtime, either. Who hasn’t held their phone while about to get into bed and decided to glance at their email? As Van den Bulck says, “It just takes a couple of seconds. You can do it with one finger.” You might have new messages from your mother or a client or a friend, and reading them might make you feel anxious or excited or angry. They probably don’t make you sleepy.

Do Not Disturb

Van den Bulck believes media content and the mindless way we consume it work together to exert a powerful influence on our sleep. “A lot of sleep experts believe that dreaming is how we process what happened to us during the day,” Van den Bulck says. “But much of what happens to us in a day is media related.

“If you mindlessly watch a movie in which a giant robot comes back from the future and tries to kill someone,” he continues, “it will come back in your dreams. The media we consume is linked to what we dream about.”

He also sees the way our media consumption has blurred the routines that once gave structure to our day. “Remember when going to bed meant going to sleep?” he asks. “Now going to bed can be hours away from going to sleep because bed is increasingly associated with leisure activities, such as playing video games or watching TV.” And ages ago, when networks broadcast one episode of a show at a time, the suspense from that final scene held until you could watch the next episode the following week. But when the next episode is ready to watch as soon as you swipe the screen, who can resist the hook of finding out what happened?

According to Van den Bulck, such tantalizing stimulation can easily overshadow the messages our bodies send to tell us we’ve reached satiety or that we’re ready to fall asleep.

And that, he says, isn’t a change people should take lying down.