--noun

1. contact: a thin curved glass or plastic lens designed to fit over the cornea in order to correct vision or to deliver medication.

A contact lens, or simply contact, is a thin lens placed directly on the surface of the eye. Contact lenses are considered medical devices and can be worn to correct vision, or for cosmetic or therapeutic reasons. In 2004, it was estimated that 125 million people worldwide use contact lenses, including 28 to 38 million in the United States.