The cornea and lens combine to focus visual images on the back of the eye. When the overall shape of the eye is incorrect or when the curvature of the cornea is incorrect, the visual images are not in focus. The cornea accounts for approximately two-thirds of the focusing power of the eye. By surgically changing the corneal curvature, the rays of light are focused clearly on the retina, and most or all of the blur can be eliminated.

Laser vision correction is an exciting medical tool uniquely suited for refractive corneal surgery. It is not really new. Around the world, millions of procedures have been performed since the 1980s. Laser In Situ Keratomileusis (LASIK) and Photo-Refractive Keratectomy (PRK) are two surgical techniques which utilize lasers to reshape or change the curvature of the cornea.