It is not a disease entity per se,but a symptom complex occurring as a result of deficiency or abnormalities of the tear film.it is common among the elderly,in whom tear secretion is usually reduced.Drugs such as diuretics and agents with anticholinergic action(I.e certain drugs used in treatment of depression, Parkinson's disease and bladder instability may also induce the symptoms of dry eye.

Symptoms: most times patient experience feeling of dryness in the eyes,irritation, presence of foreign bodies(sandy/gritty) sensation, and also ocular discomfort.

Causes:The occurrence could be as a result of the following mucin deficiency,This occurs when goblet cells are damaged causing dryness (xerophthalmia).
Aqueous tear deficiency, which may be seen in cases of hyposecretion.

Treatment: Treatment modalities for dry eyes include,supplementation with tear substitutes.This involves the use of artificial tears as supplement for treatment of dry eyes.
Simple ointment, which helps to give prolong lubrication, particularly at night when tear secretion is minimal.
Treatment of any associated disease would help reduce the symptoms of dry eyes.
Cc: Richieray,Dr steroid.