Several factors can cause the water from the tear film to evaporate too quickly, or for overall tear production to simply decrease. These include:
- Evaporation of the water from the tear film - Blepharitis (eye inflammation), decreased production by the oil glands of the eyelids, or thyroid disease cause water evaporation in the eye.
- Decreased sensation of the cornea - Corneal sensation is part of the tear-making response, so eyes with decreased sensation will tear less. Long-term contact lens wear and certain viral infections are common causes.
- Damage to the tear glands (also called the lacrimal glands) - Most commonly causes by Sjogren's syndrome, a chronic inflammatory disease. In Sjogren?s syndrome, mucous membranes, especially in the eyes and the mouth, become extremely dry. Primary Sjogren's occurs alone with no other associated disorders, while secondary Sjogren's is brought on by other autoimmune disorders, such as lupus or rheumatoid arthritis.