干眼症（英语：Keratoconjunctivitis sicca）是由于眼泪的数量不足或者质量差，导致的眼部干燥的综合症。严重的干眼可以导致角膜上皮的损伤。

Keratoconjunctivitis sicca (KCS), also called dry eye syndrome (DES) or keratitis sicca, is an eye disease caused by eye dryness, which, in turn, is caused by either decreased tear production or increased tear film evaporation. It is found in humans and some animals. KCS is the most common eye disease, affecting 5 - 6% of the population. Prevalence rises to 6 - 9.8% in postmenopausal women, and as high as 34% in the elderly. The phrase "keratoconjunctivitis sicca" is Latin, and its translation is "dry [inflammation] of the cornea and conjunctiva".