Research shows that too much exposure to light at night can mess with your sleep. This is especially true if you are exposed to the bright blue light from cell phones, TVs, laptops, and energy-efficient light bulbs. Light at night can affect your body’s inner clock—the circadian rhythm—and in turn, your sleep. All light has this effect, but light with blue wavelengths can impact sleep even more. It can boost levels of the stress hormone cortisol—which keeps you awake and alert. Night time light also hinders the release of melatonin, the hormone that helps you go to sleep.

So turn off device screens before bedtime. Dim the lights to help soothe and relax you and get you to sleep.