Dark circles can be mulifactorial. Anything that causes stress to your eyes like lack of sleep , computers , allergies , dehydration , anemia , cosmetics , lack of vitamins and it could be familial. Treatment depends on taking care the causative factor. Skin lightening agents and certain chemical peel  with lifestyle modification would help.

Hi there are many reasons for dark circles like sleeping less or at the same time sleeping more also causes dark circles , stress , vision problem May also cause it... Add more of fruits to your diet and drink plenty of water to maintain your skin tone. .. for complexion contact dermatologist....