Photorefractive keratectomy (PRK) is a type of refractive surgery that reshapes the cornea using an excimer laser to correct vision problems such as myopia, hyperopia, and astigmatism. Unlike LASIK, PRK involves removing the corneal epithelium, allowing the laser to access the corneal stroma directly, which can result in a longer recovery time but is beneficial for patients with thin corneas or dry eyes.