Skin around eyes is the thinnest and that is why poor blood circulation in that particular area appears more prominently in the form of dark circles. The best treatment to treat dark circles is to increase oxygen circulation in body with the help of exercises, yoga, splashing eyes with cold water 2-3 times a day, having plenty of water throughout the day,  a balanced diet, eat more iron and zinc containing foods like dates, nuts and dry fruits. Many topical creams that contain kojic acid helps to reduce dark circles but they should be taken after consulting a good dermatologist only. Some latest treatments like light therapy, skin resurfacing and injectable fillers give faster and long lasting results, but before you choose one it's important to determine the cause.

Treatment for dark circle:-Apply Biluma Cream/ Kojivit Gel/ Kojic Cream for application once daily for 2 weeks. Then apply Cernor Kit everyday ( expensive but effective) for 1 month. Check blood test for Haemoglobin. Fruit Peels with Lactic / Glycolic acid to be done by a dermatologist near you .