Dark circles under or around your eyes make you look tired, but there plenty of other reasons you might get them. Here's the science behind dark eye circles, and how you can try to avoid them.
As this video from the SciShow YouTube channel explains, the main reason why your skin might look darker in the area around your eyes is because the skin is thinner in that area and there's less fat to hide the tiny blood vessels there. Additionally, the natural pigmentation of your skin, or the amount of melanin in the skin in that area, is a factor as well. So genetics play a huge part, and there may not be a way for you to get rid of them entirely. That said, there are some things that can make them much worse.
If you don't get enough sleep or you're always stressed out, your body will produce more cortisol in an effort to keep you alert. Over time, cortisol can constrict blood vessels or, in this case, dilate them and make the ones under your eyes bigger. Allergies can be a major cause as well. Allergic reactions cause your body to release histamines, which also dilate blood vessels. Also, sunlight can damage the skin cells around your eyes and kill them off if you don't protect your face. Less skin cells means thinner skin, which means darker circles. And lastly, as you get older, you have less fat underneath the skin and it gets thinner.
The best things you can do to fight off those dark circles is to wear sunscreen, get plenty of sleep, take your allergy medication, and avoid stress as much as possible. Clearing your sinuses can help too if you have any nasal congestion.
Why Do I Get Dark Circles Under My Eyes? [YouTube]