PRK, or photorefractive keratectomy, laser eye surgery is similar to LASIK eye surgery in the sense that both procedures employ a computer-controlled excimer laser to reshape the cornea of the affected eye. However, during the LASIK procedure, the surgeon preserves the epithelium (the outermost protective layer of the eye) by creating a flap. During PRK vision correction, the epithelium is removed by gently scraping the surface (i.e. no flap is created). Anesthetic drops in the eye ensure that the patient experiences as little discomfort as possible.