ABSTRACT
Corneal refractive procedures change the corneal curvature in an attempt to correct myopia or hyperopia. Radial keratotomy (RK) flattens the center of the cornea through peripheral corneal incisions. Photorefractive keratectomy (PRK) reduces or increases corneal curvature by direct photoablation of the corneal stroma, while laser assisted in situ keratomileusis (LASIK) performs the same task after a flap is created and is lifted up.
