LASIK is a type of eye surgery to reduce nearsightedness and sometimes astigmatism and farsightedness. LASIK is the abbreviation for laser in situ keratomileusis. In this procedure an eye doctor removes very thin layers of tissue from the cornea. The cornea is the clear dome on the front of the eye.
Nearsightedness is when you have trouble seeing distant objects clearly. In farsightedness, it is difficult to see nearby objects clearly. Astigmatism is blurry vision that occurs when the cornea is uneven.
LASIK only corrects focusing problems that can also be corrected by glasses or contact lenses.
If you have perfect vision, light should pass through your cornea and lens and reach a focus point on the back of your eye (the retina). Nearsightedness occurs when your eye is too long and the focus point is in front of the retina. Farsightedness is when the eye is too short or your cornea is too flat, causing the focus point to be behind the retina. In astigmatism, the cornea is uneven and your eye cannot focus light rays sharply at any distance.
During LASIK, the surgeon uses a laser to remove thin layers of tissue from the cornea. This changes the shape of the cornea so that light rays can focus on or closer to the retina, which improves your vision.
LASIK may correct your vision and reduce your need for glasses or contact lenses. It can be used to improve mild to moderately severe nearsightedness, mild farsightedness, and astigmatism. Be sure to talk to your doctor about your chances for improved vision.
Often both eyes are done at the same time. However, your doctor may prefer to do one at a time.
Do not wear rigid contact lenses for 3 weeks before the surgery or soft contact lenses for 2 weeks before being evaluated for surgery. Do not wear any makeup the day of surgery.
The surgery is done in a special office with laser equipment. You will need to arrange for someone to take you home about an hour after the surgery. Allow for time to rest at home while your eyes heal.
The doctor numbs your eyes with special eyedrops. Then he or she uses a special instrument to cut part way into the cornea. The doctor leaves one edge of this tissue attached to your eye, forming a flap. The flap is then opened, like a door on a hinge. Then your doctor uses the laser to remove thin layers of the inside of the cornea (the stroma) until it is the right shape to improve your vision. The doctor then closes the flap, which stays in place without stitches.
Usually you will be able to see well in a few hours. You will have little or no pain. Your eyes may feel dry for a few days or weeks. Your doctor can prescribe eyedrops to reduce the dryness.
As with any surgery, the results are not guaranteed. Some possible risks include:
Many people (90% or more) have at least 20/40 vision after LASIK. They do not need glasses or contacts for driving and many other activities.
Healing following LASIK is usually faster than that following other types of refractive surgery because the flap (outer part of the cornea) is put back on the eye. This step also reduces the chance of infection.
LASIK can correct for greater degrees of nearsightedness than can some other types of refractive surgery.
If needed, your surgeon can repeat the procedure to fine-tune your vision.
Call your doctor immediately if you have:
Reviewed and approved by the Wilmer Eye Institute of The Johns Hopkins Medical Institutions, Baltimore, MD. Web site: http://www.wilmer.jhu.edu
Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.
HIA File EYE4227F.HTM Release 9.0/2006
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