Photorefractive keratectomy (PRK) is a type of laser eye surgery. PRK uses an ultraviolet laser to reshape the cornea (outer surface of the eye). PRK can correct astigmatism, nearsightedness, and farsightedness. Unlike LASIK, PRK does not create a flap in the eye. Although no surgery is completely safe, PRK has less complications or side effects than LASIK. Some patients who can not have LASIK may be able to get PRK. PRK is especially preferred over LASIK for people with high prescriptions, thin corneas, and people who are more likely to get eye injuries, such as athletes or police officers. Potential side effects or complications include seeing haloes, starbursts, or glare, corneal haze, dry eye, infection, blurry vision, double vision, and the continued need for glasses or contact lenses. Side effects are more likely if an old or obsolete laser is used, which many clinics still use. Side effects are usually temporary but may become permanent. Some temporary side effects may be caused by the eye drops used, and not the surgery itself.