Entropion

Entropion is an eyelid malposition in which the eyelid margin — usually the lower one — turns inward, causing the eyelashes to rub directly against the eye's surface with every blink.

This constant friction can cause chronic irritation, redness, a foreign-body sensation, and, if left uncorrected, can damage the cornea over time. It's more common in older adults, due to age-related laxity of the eyelid tissue, though it can also result from scarring or muscle spasm.

Definitive treatment is surgical: the eyelid is repositioned to restore its normal alignment. It's an outpatient procedure that resolves both the discomfort and the risk of long-term corneal damage.