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.
How does it work?
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.
When is it used?
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.
How do I prepare for the procedure?
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.
What happens during the procedure?
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.
What happens after the procedure?
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.
What are the risks of LASIK?
As with any surgery, the results are not guaranteed. Some
possible risks include:
- Your eyes may be over-corrected, and you may become
farsighted.
- You may not get enough correction and still need glasses
for distance vision.
- You may have scarring that causes glare or an irregular astigmatism.
- You may need reading glasses for close vision. After
LASIK some people need to begin using reading glasses
sooner than they would have without it. Remember that
most people need reading glasses after about age 40
because of normal changes in their eyes.
- Rarely, the cornea gets inflamed and may need treatment with eyedrops or further surgery.
What are the benefits of LASIK?
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.
When should I call my doctor?
Call your doctor immediately if you have:
- unusual pain
- a sudden loss of vision
- a lot of drainage from your eye.
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 eye4227.HTM Release 9.0/2006. Copyright © 2006 McKesson Corporation and/or one of its subdiaries. All Rights Reserved.
Top of Page
|