If you’re like 60% of Americans, you’re probably using the computer within an hour of going to bed. Unfortunately, this is counterproductive to your sleep. Why? The artificial light that computer screens emit not only make you feel more alert, but they also suppress the hormone that promotes sleep, melatonin. The result: You sleep less and feel more tired. Forget about reading your emails, the news, or casually browsing, and get into the habit of shutting down your computer earlier.