PRK permanently reshapes the cornea to treat refractive errors like nearsightedness, farsightedness, and astigmatism, so the results should last a lifetime. However, most adults undergo changes to their eyes at around the age of 40 that make it more difficult to focus on objects up close. This condition, presbyopia, is a natural part of the aging process and can still occur after PRK. If you should develop presbyopia after PRK, discuss solutions with your ophthalmologist.