Men and women of all ages get these dark circles for a variety of reasons. Sometimes the cause is biological, caused by dark skin pigments of molecules of Hemosiderine from blood cells. Because the skin of the under eye area is so delicate, tiny blood vessels beneath the skin can be ruptured by rubbing or this can even happen spontaneously if the eyes are already irritated due to allergies or other reasons. If the blood vessels rupture, these molecules containing iron that gives them the dark appearance get released into the underneath layer of skin and because this is so thin, show through and can be seen from the outside. Unless you can find the cause, this is tricky to deal with as the pigmentation builds up more quickly than it is absorbed, so the condition worsens.
