There's a million reasons to get a

There's a million reasons to get a good night's rest, but one of them is the simple fact that people tend to look terrible when they're exhausted.

In fact, a recently published study in the journal Sleep showed that eyes get more swollen and red, eyelids get droopier and skin gets more wrinkled when people skimp on shuteye. Meanwhile, another study showed that getting eight hours of sleep makes faces appear more attractive and healthier, compared with the faces of people who stay up all night.

But why do the eyes and skin on our face seem so affected by sleep (or lack thereof)?

Dr. Sherrif F. Ibrahim, M.D., Ph.D., assistant professor in the Department of Dermatology at the University of Rochester Medical Center, says that it has to do water retention, and the fact that the skin of the upper and lower eyelids is the the thinnest skin on our bodies.