June 3, 2013 —

Science Daily/Mayo Clinic

Smartphones and tablets can make for sleep-disrupting bedfellows. One cause is believed to be the bright light-emitting diodes that allow the use of mobile devices in dimly lit rooms; the light exposure can interfere with melatonin, a hormone that helps control the natural sleep-wake cycle. But there may be a way to check your mobile device in bed and still get a good night's sleep. A Mayo Clinic study suggests dimming the smartphone or tablet brightness settings and holding the device at least 14 inches from your face while using it will reduce its potential to interfere with melatonin and impede sleep.

"There's a lot of concern about using mobile devices and that prompted me to wonder, are they always a negative factor for sleep?" Dr. Krahn says. "We found that only at the highest setting was the light over a conservative threshold that might affect melatonin levels. If it's at the mid setting or at a low setting it's bright enough to use."

http://www.sciencedaily.com/releases/2013/06/130603163610.htm