ENTROPION

turning in of the border of the lower eyelid, a condition sometimes occurring in elderly persons. It is caused by (1) spasms of the orbicularis oculi, a muscle that extends along the lid margin and functions during winking, and (2) relaxation of the orbital septa, membranes of the eye socket that support the lids. The turning in of the lid margin allows the eyelashes to rub against the cornea, with resultant irritation. Ulceration of the cornea may be a complication. The treatment is surgical correction of the abnormality. Entropion may also occur as a complication of other eye diseases. Compare ectropion.