The corneal specialists also are involved in refractive surgery, which is the general term referring to many different procedures to correct visual perception or focus, with the objective of reducing or eliminating the need for glasses and contact lenses. These procedures include:
LASIK (laser-assisted in situ keratomileusis) is an outpatient refractive surgery procedure used to treat nearsightedness, farsightedness and astigmatism. A laser is used to reshape the cornea — the clear, round dome at the front of the eye — to improve the way the eye focuses light rays onto the retina at the back of the eye.
With LASIK, an ophthalmologist creates a thin flap in the cornea using either a blade or a laser. The surgeon folds back the flap and precisely removes a very specific amount of corneal tissue under the flap using an excimer laser. The flap is then laid back into its original position where it heals in place.
For people who are nearsighted, LASIK is used to flatten a cornea that is too steep. Farsighted people will have LASIK to achieve a steeper cornea. LASIK can also correct astigmatism by shaping an irregular cornea into a more normal shape.
LASEK eye surgery is a variation of PRK to correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. LASEK combines certain methods from both LASIK and PRK.
Like other types of laser refractive surgery, LASEK works by reshaping the cornea using an excimer laser, allowing light entering the eye to be properly focused onto the retina for clearer vision without eyeglasses or contact lenses. The LASEK procedure involves a little of both LASIK and PRK. Like in PRK, the corneal epithelium is separated from the underlying stromal layer. But instead of completely removing and discarding the epithelial tissue, the LASEK surgeon pushes the ultra-thin epithelial “flap” to the side (it remains attached to the eye on one side, like the thicker corneal flap made in LASIK), exposing the corneal stroma for laser reshaping.
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. During PRK, a laser is used to reshape the cornea. This laser, which delivers a cool pulsing beam of ultraviolet light, is used on the surface of the cornea.