kerat(o)- Also keratino- and cerato-.
Horny tissue; the cornea.
[Greek keras, kerat-, horn.]
Keratin is a fibrous protein that forms the main structural constituent of hair, feathers, hoofs, horns, and the like. Several terms in kerato- refer to keratin, such as keratosis, a horny growth, especially on the skin. The rarer form keratino- derives from keratin by adding the linking vowel -o-; an example is keratinocyte, an epidermal cell which produces keratin. Occasionally the spelling is cerato-: ceratopsian (Greek ops, face), an herbivorous Cretaceous dinosaur such as triceratops, with a beaked and horned head.
Several medical terms refer to the cornea, the transparent layer forming the front of the eye (whose name derives from cornu, the Latin equivalent of Greek keras). Examples are keratectomy (Greek ektomē, excision), surgical removal of a section or layer of the cornea, usually performed using a laser; and keratoplasty (Greek plastos, formed, moulded), surgery carried out on the cornea, especially corneal transplantation.