More than 70 million Americans suffer from chronic sleep deprivation or other sleep disorders, and the American Sleep Association says that most of these cases begin when people fail to adhere to good practices at bedtime. One of the keys to facilitating healthy sleep is leaving electronics out of the bedroom—especially handheld smartphones, tablets, and laptops, which can disrupt your body's natural sleep process if they're used frequently enough.
The reason why sleep experts harp on personal electronic devices is because these gadgets (which are often equipped with LED displays) emit very bright light, including the blue aspect of the light spectrum, which are especially harmful to a healthy sleep routine. "Blue is the fifth color in the rainbow," says Dr. Jay Neitz, a professor and researcher in the department of ophthalmology at the University of Washington, where he studies vision disorders among other eye health issues. "Red is at one end of the spectrum, whereas violet is at the other—blue is in the middle of the color spectrum, but leans towards the short wavelength end."
It's important to note all kinds of light—even sunlight—contain blue hues, which is a color that is transmitted as a short wavelength, meaning it produces a higher amount of energy than others, Neitz says. Many people believe using special features to minimize blue light exposure, including apps like Apple's "Night Shift" or special-order eyewear, will allow them to use electronics before bed without disrupting sleep schedules. But, according to Neitz, any electronic that emits light could potentially impact your body's circadian rhythm.
When nighttime falls, darkness generally encourages your body to produce melatonin hormones that allows us to feel tired and to get to bed—but Neitz says that any source of light can affect your circadian rhythm, especially if you lay in bed while using your smartphone right before you try to sleep.
"Light sets our internal clock. If your clock tells you it's time for bed, but you're still being exposed to a lot of light, your brain decides that it needs to reset your clock to a later time," Neitz says. "This makes it harder to get up in the morning, and increasingly difficult to get good quality sleep if your clock is being constantly unnaturally delayed." If all light could potentially impact our sleep, why is there so much talk of blue light? Since blue light emits a more energetic wavelength, it's "more effective than other colors at resetting our internal clock," Neitz says.
Rather than splurge on pricey blue-light eyewear or try to maximize screen time with blue-light-reducing apps, Neitz believes the best way to improve your quality of sleep is to curb screen time during the night. Research published in the Journal of Adolescent Health in 2015 found that limiting nighttime exposure to blue light, in particular, can increase how many hours you sleep if you've previously had trouble sleeping. This is especially true if you're known to use your phone before bed. Another 2014 study, published in the journal Sleep, found that powering down electronics at least 30 minutes before bed (if not an hour or two beforehand) can help reduce light's stimulating effect on your brain and sleep routine.
If you're hoping to revolutionize your bedtime routine, Netiz stresses that all forms of electronics should stay out of the bedroom—including desktops, televisions, and video games. It seems that cutting down your pre-bedtime electronic use may help you to fall asleep faster, but it could also help you stay asleep longer and wake up feeling refreshed, too.