We’ve all been there: You catch a glimpse of yourself in the mirror and see the eyes of a tired woman staring back at you. But a full night of shut-eye isn’t enough to erase those dark circles, says Charlotte Clark, a dermatologist in New York City. It may help diminish their appearance a bit, but to get rid of circles for good, first consider their source.

 

Why They Appear

Genetics are the biggest culprit. If you inherit fair or thin skin under the eyes, it’s more obvious when blood pools there (often because of slower circulation from lack of sleep). This accumulation causes fragile capillaries to stretch and leak.
 
Age is another factor. Over time, skin loses collagen and thins, so veins show through more prominently. Sunbathing speeds up this process by breaking down collagen and mottling skin color.
 
Seasonal allergies are to blame for many people. “They trigger the release of histamines in the body, which in turn inflame blood vessels and cause swelling,” says Ranella Hirsch, a dermatologist in Boston. To determine why your circles happen, gently stretch the skin under your eyes. If that area becomes darker, the circles are probably due to genetics or aging. If the color doesn’t change, UV rays or allergies are probably the cause.