If you're tired of wearing glasses or contact lenses, you may be considering LASIK eye surgery. Before you sign up for the surgery, get a clear picture of what you can expect.

What is LASIK?

In LASIK (Laser-In-Situ-Keratomileusis), a laser is used to carefully reshape a very thin layer of your cornea - the clear outer layer of your eye which covers your iris (the colored part). This alters the focusing power of your cornea to better suit the shape and focal length of your eye, improving your vision. The majority of patients no longer require glasses or contacts after LASIK surgery.

Why would I want laser vision correction?

Probably because you have a condition called nearsightedness (myopia) or farsightedness (hyperopia). When light rays and images enter the eye, they get focused by the cornea and lens of the eye onto the retina - a thin layer of tissue in the back of the eye that processes images and sends them to the brain. However, if the shape of the eye and the power of the cornea do not focus the image clearly on the retina, a blurred image will result. Traditionally this would be treated with glasses or contact, but LASIK surgery allows us to gently reshape the to make a clear image on the retina.

How does laser vision correction compare to glasses or contacts?

Glasses and contacts temporarily adjust the eye's refractive power to focus images on the retina while you're wearing them, but don't actually "cure" the underlying problem. Laser vision correction offers a more permanent solution by surgically reshaping your cornea.

What's the difference between PRK and LASIK?

In PRK (photorefractive keratectomy), the surgeon gently scrapes the surface layer (epithelium) from the cornea prior to using the laser for corneal reshaping. This epithelial layer will grow back over the surface of the cornea during the first 3-4 days after your procedure. During this time you may experience some discomfort and have blurred vision until the eye is completely healed.

In LASIK, a special instrument is used to cut a "flap" in the cornea. This flap is then lifted prior to the laser corneal reshaping and is placed back into position at the end of the procedure. This helps to speed the healing process and minimize discomfort after the procedure. Both LASIK and PRK have their own risks and benefits. Your surgeon will help you decide which procedure is best suited for your eyes.

How well will I see after the procedure?

After surgery, almost all patients see 20/40 or better. Most patients see 20/25 or better, and many even see 20/20. Sometimes enhancement surgery is needed to "fine tune" the results and maximize your visual acuity. Laser vision correction cannot guarantee that you won't need glasses or contact lenses after the procedure, but it will decrease your dependence on corrective lenses. So while you may still need to use glasses occasionally to see at night or while driving, you'll probably need them less often for the many other tasks you do.

How painful is the procedure?

You'll feel no pain during the surgery. The laser doesn't actually burn tissue away; it breaks the bonds between molecules to "vaporize" corneal tissue. However, there may be some pain in the days following the procedure. Usually, if you do feel pain, it subsides after a couple of days. Furthermore, your doctor can prescribe medication to make this time a little easier. Most patients do have some irritation, light sensitivity, or watering of the eyes the first few days after the procedure.

How soon can I go back to work?

Two or three days after the procedure, your vision will improve well enough for you to perform most visual tasks. You probably will be ready to drive yourself to work by the second or third day after the procedure.

Am I a Good Candidate for LASIK?

• You should be at least 18 years old (21 for some lasers), since the vision of people younger than 18 usually continues to change.
• You should not be pregnant or nursing as these conditions might change the measured refraction of the eye.
• You should not be taking certain prescription drugs, such as Accutane or oral prednisone.
• Your eyes must be healthy and your prescription stable. If you're myopic, you should postpone Lasik until your refraction has stabilized, as myopia may continue to increase in some patients until their mid-to late 20s.
• You should be in good general health. LASIK may not be recommended for patients with diabetes, rheumatoid arthritis, lupus, glaucoma, herpes infections of the eye, or cataracts. You should discuss this with your surgeon.
• Weigh the risks and rewards. If you're happy wearing contacts or glasses, you may want to forego the surgery.
• Understand your expectations from the surgery. Are they realistic?
• If you are over the age of 40, ask your doctor if you're a candidate for monovision. This procedure involves correcting one eye for distance vision and the other eye for near vision. LASIK cannot correct presbyopia and all patients over the age of 45 will require monovision or reading glasses for their near vision after surgery. If your doctor thinks you're a candidate, ask about the pros and cons.