Tears are produced in the tear gland. By lubricating the eyes, tears play a vital role in the maintaining the health of the eye. When the eye is irritated excess tears are produced. People are not always aware of the eye irritation, but instead may notice the overproduction of tears.
Tears normally drain into small holes located in the inside corner of the upper and lower eyelids.
The tears then collect in the tear sac. The tear sac lies under the skin between the corner of the eye and the nose. Next, the tears flow through a small tube, called the nasolacrimal duct, into the nose. The tears are pumped through this drainage system by the opening and closing of the eye. A blockage in any part of this drainage system can prevent tear drainage and lead to excess tears running out of the eye and down the cheek.