Source : Webster's Revised Unabridged Dictionary (1913)

Keratonyxis \Ker`a*to*nyx"is\, n. [Gr. ke`ras, -atos, horn + ?
   puncture.] (Med.)
   The operation of removing a cataract by thrusting a needle
   through the cornea of the eye, and breaking up the opaque
   mass.