contact lens, a small, curved lens, primarily plastic in composition, shaped to fit the person’s eye either to correct refractive error or to enhance appearance. The two primary forms of contact lenses are (1) rigid gas-permeable lenses, which are small, are durable, and have little to no water absorption; and (2) soft lenses, which are larger, are more fragile, and have a 30% to 70% water content. Contact lenses float on the precorneal tear film.
