Source : Webster's Revised Unabridged Dictionary (1913)

Cornea \Cor"ne*a\ (k?r"n?-?), n.; pl. {Corneas} (-?z). [Fem.
   sing., fr. L. corneus horny, fr. cornu a horn. See {Horn}.]
   (Anat.)
   The transparent part of the coat of the eyeball which covers
   the iris and pupil and admits light to the interior. See
   {Eye}.

Source : WordNet®

cornea
     n : transparent anterior portion of the outer covering of the
         eye; it covers the lens and iris and is continuous with
         the sclera
     [also: {corneae} (pl)]