Dry eye syndrome ("dry eye") refers to a condition where there is a decline of the quantity of tears keeping the eye moist. Typically, patients suffering from dry eyes experience eye irritation or pain, although the dry eye effect may come and go. Many people with dry eyes also experience a sandy or gritty sensation that, if left untreated, can lead to scarring or ulceration of the cornea, and possible loss of vision.

There are a variety of causes of dry eye syndrome, including immune system disorders, overly quick evaporation of tears, or mishapen eye features. However, the most common cause of dry eye syndrome is natural aging of tear glands in the eye.

There are a variety of treatments available to help alleviate dry eye, including artificial tears, ointments, and orally taken medications designed to stimulate increased production of natural tears.