LASIK, or "laser-assisted in situ keratomileusis," is the most commonly performed laser eye surgery to treat myopia (nearsightedness), hyperopia(farsightedness) and astigmatism.
Like other types of refractive surgery, the LASIK procedure reshapes the cornea to enable light entering the eye to be properly focused onto the retina for clearer vision.
In most cases, laser eye surgery is pain-free and completed within 15 minutes for both eyes. The results — improved vision without eyeglasses or contact lenses — can usually be seen in as little as 24 hours.
If you're not a good LASIK candidate, a number of other vision correction surgeries are available, such as PRK and LASEK laser eye surgery and phakic IOL surgery. Your eye doctor will determine if one of these procedures is suitable for your condition and, if so, which technique is best.
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How Is LASIK Surgery Performed?
First, your eye surgeon uses either a mechanical surgical tool called a microkeratome or a femtosecond laser to create a thin, circular "flap" in the cornea.The surgeon then folds back the hinged flap to access the underlying cornea (called the stroma) and removes some corneal tissue using an excimer laser.
This highly specialized laser uses a cool ultraviolet light beam to remove ("ablate") microscopic amounts of tissue from the cornea to reshape it so it more accurately focuses light on the retina for improved vision.
For nearsighted people, the goal is to flatten the cornea; with farsighted people, a steeper cornea is desired.
Excimer lasers also can correct astigmatism by smoothing an irregular cornea into a more normal shape. It is a misconception that LASIK cannot treat astigmatism.
