Entropion is a turning in of the eyelid.  This typically occurs in the lower, and sometimes the upper, eyelid and the skin and lashes rub against the cornea causing significant irritation to the surface of the eye. Usually this occurs due to increased laxity of the eyelid as we age.  An entropion can also be caused by injury, congenital defect, skin infections as well as inflammatory conditions. An entropion is generally corrected through a surgical procedure.