Most refractive surgical procedures change the curvature of your cornea to improve your eyesight. Not everyone is a good candidate for surgery, and your eye doctor will evaluate your eyes and health to recommend which of these available procedures may be right for you.
Laser-assisted in-situ keratomileusis (LASIK)
This is the most popular and most commonly performed refractive surgery. During LASIK surgery, the ophthalmologist makes a thin, circular hinged cut in your cornea, creating a flap. Then he or she uses a type of laser that doesn't produce heat to remove layers from the centre of your cornea to flatten its domed shape if you are nearsighted, steepen the dome if you are farsighted or smooth the dome for astigmatism. The surgeon then repositions the corneal flap.
The procedure usually takes about 15 minutes for both eyes. Side-effects may include dry eyes and infections, but they are rare.
Laser-assisted subepithelial keratomileusis (LASEK)
LASEK differs from LASIK in that the surgeon doesn't create a flap in the cornea itself but, only in the cornea's thin protective cover called the epithelium. The next step is the same laser procedure used in LASIK to flatten or steepen the curves of the cornea. The surgeon finishes by repositioning the epithelial flap.
The procedure takes about 10 minutes for each eye.
Photorefractive keratectomy (PRK)
PRK was the first type of surgery developed to correct refractive errors. This surgery is still common, though not as popular as LASIK, partly because PRK has a longer recovery time. In PRK, the surgeon completely removes the epithelium, which will grow back and conform to the new shape of your cornea.
Epi-LASIK
This is a recently developed procedure that's somewhat of a cross between LASIK and LASEK, with some differences designed to solve some of the problems associated with those other procedures.
Conductive keratoplasty (CK)
CK can correct mild farsightedness and help people over 40 who have presbyopia, a version of farsightedness. Using radiofrequency energy, this procedure applies heat to tiny spots around the cornea.
The heat causes the cornea to stretch, changing its curvature to a degree that depends on the number and spacing of the spots and the way in which the cornea heals after treatment. While the change lasts a long time, it's not permanent.
Refractive lens exchange
For people with presbyopia and a lot of farsightedness, lens replacement surgery may be an option. The surgeon replaces your eye's lens with an artificial intraocular lens.
Eye surgery risks
All surgery has risks, and those in refractive surgery include eye infection and irritation, scarring of the cornea (primarily a LASIK risk), dry eyes, blurry vision, problems with glare or seeing halos around lights and vision loss.
It's also possible that surgery may overcorrect or undercorrect your vision or that improvements don't last. Make sure you understand the risks and benefits, if you are considering eye surgery to correct refractive errors.