Just a few decades ago, people who needed glasses or contact lenses wore them their entire lives. Today, people with refractive errors such as nearsightedness or farsightedness can permanently correct their vision surgically, and abandon glasses and contact lenses altogether. Many options for corrective eye surgery exist, but not all corrective methods work for every type of eye problem.
LASIK
LASIK, which stands for laser-assisted in situ keratomileusis, uses laser beams to change the shape of the cornea, the clear dome-shaped covering of the front of the eye. Nearsightedness and farsightedness occur because light rays bend and focus in front of, or behind, the retina instead of directly on it. Reshaping the cornea adjusts the way light bends and focuses on the retina. LASIK, the most popular form of corrective surgery according to the Merck Manual, can correct nearsightedness, farsightedness and astigmatism, an irregularly shaped cornea.
LASIK creates a small flap in the cornea using laser or a cutting tool, and then reshapes the corneal tissue beneath the flap with a laser. After the flap is replaced, it acts as a bandage to protect the cornea.LASIK causes little pain and almost immediate vision improvement. People whose corneas are thinner than normal can't have LASIK surgery, All About Vision states.
Wavefront LASIK, also called Custom LASIK, more accurately measures and corrects specific vision problems by creating an optical map of the eye via laser, the Ohio State Medical University explains.
PRK
PRK, which stands for photorefractive keratectomy, was the forerunner of LASIK, but still has proponents today. PRK, or surface ablations, removes tissue directly from the cornea surface without creating a flap. Nerves often heal faster after PRK than LASIK, which may reduce the incidence of dry eye, a complication that can damage the cornea in rare cases after LASIK. PRK often causes more pain and a longer healing time than LASIK.
Implantable Lenses
People with severe nearsightedness, also known as high myopia, may benefit from implantable lenses, which are placed in front of, or behind, the natural lens. The natural lens is sometimes removed from the eye, especially for people who have presbyopia and need reading glasses in addition to nearsightedness, the Merck Manual states. Implantable lenses carry a higher risk of infection in the eye after surgery than LASIK or PRK.
Refractive Lens Exchange
Refractive lens exchange removes the lens of the eye, just like cataract surgery, and replaces it with an artificial lens of a different shape to correct severe farsightedness, according to Casey Eye Institute.
