Photorefractive Keratectomy (PRK)
PRK is a procedure where the outer membrane of the cornea is removed by an instrument. Then the Excimer laser is used to flatten the top surface of the cornea, 0.2 microns at a time (less than the thickness of a human hair). This flattens the curvature of the cornea, allowing images to be more sharply focused on the retina. The laser part of the surgery takes less than two minutes.
Following the surgery, a special contact lens is applied and worn for three days. It takes approximately three days for the eye surface membrane to heal and a few weeks to months for vision to fully improve to its best level. PRK is beneficial for patients with thin corneas.