The National Eye Institute defines Dry Eye as:

"...a disorder of the tear film due to tear deficiency or excessive tear evaporation which causes damage to the interpalpebral [the exposed area between the upper and lower lids] ocular surface and is associated with symptoms of ocular discomfort."

Dry eyes result from a shortage of tears. Symptoms are hot, sandy eyes that are red and, possibly, swollen. Dry eyes can injure the eye's cornea and damage vision. They also make wearing contact lenses very difficult. This condition rarely affects just one eye.

What causes dry eyes?

Teardrops normally consist of three layers: an outer oily layer, a middle watery layer, and an inner mucus layer. Dry eyes occur when one of these layers is incomplete.

Sjogren's syndrome, a connective tissue disorder, often occurs in people who have rheumatoid arthritis or lupus. One symptom of Sjogren's syndrome is dry eyes.

Infrequent blinking, overheated and air-conditioned buildings, and certain medications (such as antidepressants, allergy medicines, and birth control pills) can aggravate dry eyes.

Often dry eyes are part of the normal aging process, and are very common among post-menopausal women.

Sometimes there is no obvious reason for the condition.

How are dry eyes treated?

This condition is not curable, although it is manageable. Your eye care specialist will prescribe moisturizing drops and ointments to ease any symptoms. S/he also might recommend changing your environment by turning down the heat or using a humidifier.

If this does not work, s/he might suggest more complex treatment, such as plugging the tear ducts. The tear ducts act as a drain for tears. Plugging the tear ducts allow tears to well up and keep the eyes moist.

Dry eyes are a chronic problem that require continued monitoring.