An eyepatch is a small patch that is worn in front of one eye. It may be a cloth patch attached around the head by an elastic band or by a string, an adhesive bandage, or a plastic device which is clipped to a pair of glasses. It is often worn by people to cover a lost or injured eye, but it also has a therapeutic use in children for the treatment of amblyopia. Eyepatches used to block light while sleeping are referred to as a sleep mask. Eyepatches associated with pirates are a stereotype originating from fiction.