The first popular laser procedure was Photorefractive Keratectomy, or PRK. This involved removing a thin layer of corneal tissue (the epithelium), using a laser to reshape the curvature, and applying a contact lens to act as a bandage allowing the epithelium to re-grow over several days. Anti-infective and anti-inflammatory drops are required for several months, and until the epithelium heals, initial comfort can be an issue.
Shortly thereafter, LASIK gained popularity given its relatively rapid healing time, quick visual recovery, and improved post-operative comfort. In LASIK, the surgeon uses the laser to create a hinged corneal flap: this allows the laser to be applied below the surface of the cornea, reducing inflammation, discomfort, and recovery time.