Do you spend countless hours at night playing video games, watching TV and trolling on social media? Are you having trouble falling asleep? Using electronic devices more often for longer periods of time has a negative impact on sleep, according to a recent study presented at a webinar hosted by the Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury Dec. 3.

Sleep-wake cycles, hormone release, body temperature and other important bodily functions are controlled by a person’s circadian rhythm over a 24-hour period of time. Light exposure can disrupt sleep and affect the circadian rhythm, which is why research is looking at how the increased use of electronics may be impacting our sleep. TV, computers, tablets and cell phones all produce what is referred to as blue light waves in dark rooms during night hours.

Researchers found that levels of melatonin, the hormone that regulates sleep-wake cycles, is affected by blue light, said Mariana G. Figueiro, a professor at Rensselaer Polytechnic Institute in Troy, New York. Melatonin levels were on average 22 percent lower than in a control group after two hours of screen exposure, she said.

Not just the color of light, but the intensity level is also important, Figueiro said. The subjects watching movies had less melatonin suppression than those tested on computers because the screen was darker overall, she said.

“Computer screens have a large potential to suppress melatonin, probably even greater than iPads because they emit more light,” Figueiro said. “The bigger and brighter the screen, obviously, the more likely it is to suppress the melatonin levels.”

Length of exposure makes a difference too, the study found.

“The longer that you stay on your tablet the more likely it is that you will see melatonin suppression,” Figueiro said.

Figueiro said that turning devices off at least two hours prior to bedtime, reducing screen brightness, using white fonts with black backgrounds on computer screens and going outdoors during the day will help people who use electronic devices at night fall asleep faster and get a better night’s sleep.

The full presentation, “Detrimental Effects of Blue Light from Electronics on Sleep” and its resources are available on the DCoE website.