The Real Deal with Sleep and Screens

November 17, 2014 All posts Jared Sebastian

Pop quiz: what’s the last thing you looked at before closing your eyes to fall asleep last night?

A. The textured paper of a great book

B. The serene face of your sleeping partner

C. The flickering glow of a meditation candle

D. Instagram. Or Facebook. Or e-mail. Or really anything emanating from a glowing screen.


If you're like many Americans, you chose option D. According to the National Sleep Foundation [1], 95% of people use some type of electronics within an hour of bed at least a few times a week, with another study [2] showing that 54% check their phone while lying in bed. Not to mention the fact that, according to the Pew Research Center, 44% of people sleep next to their smartphones [3].

These findings make sense: our smartphones make us feel connected, laptops feed our need to always be “productive,” and TV’s help many of us relax after a hard day. But science suggests that these habits are damaging our sleep health, and there are all sorts of guidelines and suggestions for how and when to use screens for optimal sleep.

So what gives? Is reading your iPad in bed really destroying your body’s ability to rest, and, if so, what are we supposed to do about it?

Screen Happy, Sleep Deficient

Our environment has changed drastically in the recent past, with technology advancing at a rate that evolution can’t keep up with. Case in point, the second half of the 20th century saw the use of artificial light sources quadruple, a trend paralleled by a steady increase in sleep deficiency. [4]

On the flipside, a 2013 study showed that when people were put in an environment without any artificial light—aka a week of camping in the Rockies—they returned to normal sleep patterns, their circadian clocks completely synchronized with the sun.[5]

Artificial light can refer to a lot of things, but evidence suggests that the most sleep-antagonizing type comes from those friendly little screens that keep us entertained and informed all day long. One study showed that adults who used iPads and PC tablets at their full brightness for two hours before bedtime reduced their levels of melatonin, the sleep hormone, by 22%.[6]

With kids, the results are even more significant. Studies show that the more screen time kids get later in the day, the longer it takes to doze off [7], and adolescents’ shifting circadian rhythms make them extra susceptible to light disruption. In fact, teen sleep cycles can be disrupted by just 1/10th the amount of light it takes to affect an adult’s melatonin levels. With 72% of kids age 6-17 sleeping with at least one electronic device in their bedroom, this means many young people miss vital hours of brain-boosting sleep during the most crucial years of learning, growth, and development. [8]

The Why’s and the Eyes

The eyes may be the windows to the soul, but they’re also the key to understanding these screen-sleep disruptions. In fact, according to Charles Czeisler, a professor of sleep medicine at Harvard Medical School, “light affects our circadian rhythms more powerfully than any other drug.” [9]

This is because our eyes are one of the primary ways that our brain gets information about our environment—they’re the on-the-ground journalists reporting back to the editor-in-chief. So when it’s dark out, they tell our brain that it’s nighttime, and vice versa when it’s light, thus aligning our internal clocks with the outside world.

The primary alerting agents here are called intrinsically photosensitive ganglion cells (known by the oh-so-simple acronym ipRGCs), which take in ambient light information and communicate it to the brain. [10] With this information, the brain’s pineal gland knows when to secrete melatonin, which gradually prepares us for sleep over several hours before bedtime.

The kicker: ipRGCs are extremely sensitive to the blue light emitted by the screens of most electronic devices.

This means that looking at a backlit phone or tablet even a few hours before bedtime can cause sleep disruptions. You don’t even need to be looking directly at the screen—as long as enough of the light hits your eye, the release of melatonin is affected.

Your Screen Strategy

The sleep disruptions caused by the blue light of electronics has become such a talked-about issue that the market has responded. Apps like f.lux gradually begin warming up the colors of your screens toward sunset (using reds and yellows, which don’t affect icPRGs as much), returning them to their blue tint at sunrise. You can also take small steps to mitigate, if not eliminate, the effects of your screen by turning the brightness down and placing your device farther away from your eyes.

Of course, the best solution is to skip the screens as bedtime approaches. If you normally read on your smartphone or tablet before bed, try switching to good old-fashioned books or an e-reader. Some people protest that they hate having to stand up to turn off the light after they’re finished reading on a non-backlit device—with Reverie’s Bluetooth module, which allows you to turn off an out-of-reach lamp with the swipe of a finger, this problem is solved.

Of course, the best solution is to skip the screens as bedtime approaches. If you normally read on your smartphone or tablet before bed, try switching to good old-fashioned books or an e-reader. Reverie’s adjustable bed foundations support you to sit up in bed, which makes cozying up with a good book under the covers easier than ever.

Getting quality sleep doesn’t need to mean disconnecting from technology. With the sleep science and tips above, you should be good to turn in—without tuning out.