Some people do not produce enough tears to keep the eye healthy and comfortable. This is known as dry eye.

Tears are produced by two different methods. One method produces tears at a slow, steady rate and is responsible for normal eye lubrication. The other method produces large quantities of tears in response to eye irritation or emotions.

Tears that lubricate are constantly produced by a healthy eye. Excessive tears occur when the eye is irritated by a foreign body, dryness and when a person cries.

What are the symptoms of dry eye?

The usual symptoms include:

Excess tearing from "dry eye" sounds illogical, but if the tears responsible for maintenance lubrication do not keep the eye wet enough, the eye becomes irritated. When the eye is irritated, the lacrimal gland produces a large volume of tears that overwhelm the tear drainage system. These excess tears then overflow from your eye.