PRK
Photorefractive keratectomy, or PRK, is a type of laser eye surgery used to correct mild to moderate nearsightedness , farsightedness and/or astigmatism. All laser vision correction surgeries work by reshaping the cornea, or clear front part of the eye, so that light traveling through it is properly focused onto the retina located in the back of the eye. There are a number of different surgical techniques used to reshape the cornea. During PRK, an eye surgeon uses a laser to reshape the cornea. This laser, which delivers a cool pulsing beam of ultraviolet light, is used on the surface of the cornea not underneath the cornea, as in LASIK.

PRK is highly accurate in correcting many cases of nearsightedness. Approximately 80% of PRK patients have 20/20 vision without glasses or contact lenses one year after the surgery; 95%-98% have 20/40 or better without glasses or contacts.

Disadvantages of PRK include:

• Mild discomfort, including minor eye irritation and watering, for 1 to 3 days following the procedure.
• It is expensive, typically costing as much as LASIK, around $2,200 to $2,250 per eye.
• Somewhat longer time to best uncorrected vision (best vision is vision attained using glasses or contacts) typically patients are 80% at 1 month after surgery, and 95%-100% by 3 months after surgery. LASIK, in contrast, corrects vision much faster.
• The outcome is not completely predictable and some patients may still require glasses.