Photorefractive keratectomy (PRK) is a laser-assisted vision correction procedure that reshapes the cornea. Like other procedures of its type, including LASIK, PRK removes material from the inner layers of the cornea to compensate for myopia, hyperopia and other vision abnormalities. Where these laser procedures differ, typically, is how the outer layers of the cornea is treated. With PRK, the outer layer is completely removed and then the eye is allowed to heal on its own. After the procedure, bandage contact lenses are placed on the eye(s), helping to shield the cornea from infection and foreign material while the outer layers of the cornea heal and reform. Vision is typically obstructed while the outer layer heals, however, and patients occasionally report haziness, spots and other vision problems anywhere from the first few days to several months after the procedure.
Thanks to the evolution of technology, PRK is considered generally as effective as LASIK when comparing vision correction at the six-month mark. Because the outer layer of the cornea is removed, there is a chance of scarring complications with PRK, but this is rare thanks to improved equipment. There is also the possibility of infection, so patients undergoing PRK need to take care to protect their eyes while in their recovery period.