Three decades ago, a Russian injured in a fistfight made an office visit. Fyodorov removed glass splinters from the patient's eye. The surgery he performed fixed the damage from the injury, but surprisingly, it also improved the patient's overall vision. Fyodorov began experimenting with incisions in the cornea in other patients, until he succeeded in correcting nearsightedness in some. Due to the incisions, the central cornea becomes weakened.
Pressure pushes it outward and flattens it.
The flattening also reshapes the lens and modifies its refractive power. This change allows light to focus properly on the retina. The procedure was first performed in the United States in 1977. But PRK owes much to Fyodorov's pioneering work. In order to grasp an elementary understanding of vision-correction procedures, students should understand how the eye sees.