While many individuals think that dark circles are just due to sleep deprivation, there are many other conditions that can cause dark circles, such as aging, eye strain, and genetics. They are also more common for people who have darker skin tones (medium to deep skin tones), because darker skin tones are prone to hyperpigmentation under the eyes.

Because the skin under the eye is so thin, the blood vessels under the skin can become more visible—these dark blood vessels are what cause the dark circles. Also, if you suffer from puffy eyes or eye bags, the shadows cast from these can make the under-eye area appear darker, causing hyperpigmentation. As we age, our skin loses fat and collagen, which makes the area under the eye become even more hollow and sunken, which can make dark circles appear even worse. While getting more sleep or drinking more water can help some, most people are still left with dark circles no matter how rested or hydrated they are.