Complications that result in a loss of vision are very rare. But certain side effects of LASIK eye surgery, particularly dry eyes and temporary visual disturbances, are fairly common. These usually clear up after a few weeks or months, and very few people consider them to be a long-term problem.
Risks of LASIK include:
Dry eyes. LASIK surgery causes a temporary decrease in tear production. For the first six months or so after your surgery, your eyes may feel unusually dry as they heal. Dry eyes can reduce the quality of your vision.
Your eye doctor might recommend that you use eyedrops during this time. If you experience severe dry eyes, you could opt for another procedure to get special plugs put in your tear ducts to prevent your tears from draining away from the surface of your eyes.
Glare, halos and double vision. After surgery you may have difficulty seeing at night. You might notice glare, halos around bright lights or double vision. This generally lasts a few days to a few weeks.
Even when a good visual result is measured under standard testing conditions, your vision in dim light (such as at dusk or in fog) may be reduced to a greater degree after the surgery than before the surgery.
- Undercorrections. If the laser removes too little tissue from your eye, you won't get the clearer vision results you were hoping for. Undercorrections are more common for people who are nearsighted. You may need another LASIK procedure within a year to remove more tissue.
- Overcorrections. It's also possible that the laser will remove too much tissue from your eye. Overcorrections may be more difficult to fix than undercorrections.
- Astigmatism. Astigmatism can be caused by uneven tissue removal. It may require additional surgery, glasses or contact lenses.
- Flap problems. Folding back or removing the flap from the front of your eye during surgery can cause complications, including infection and excess tears. The outermost corneal tissue layer (epithelium) may grow abnormally underneath the flap during the healing process.
- Vision loss or changes. Rarely, you may experience loss of vision due to surgical complications. Some people also may not see as sharply or clearly as previously.
Conditions that increase risks
Certain health conditions can increase the risks associated with LASIK surgery or make the outcome less predictable. Doctors may not recommend laser refractive surgery for you if you have certain conditions, including:
- Autoimmune disorders, such as rheumatoid arthritis
- A weakened immune system caused by immunosuppressive medications or HIV
- Persistent dry eyes
- Unstable vision due to medications, hormonal changes, pregnancy, breast-feeding or age
- Keratitis, uveitis, herpes simplex affecting the eye area, glaucoma, cataracts, eye injuries or lid disorders
LASIK is usually not advisable if you:
- Have an eye disease called keratoconus, or if you have a family history of it
- Have fairly good overall vision
- Have severe nearsightedness
- Have very large pupils or thin corneas
- Have age-related eye changes that cause you to have less-clear vision (presbyopia)
- Participate in contact sports that may be associated with blows to the face
If you're considering LASIK surgery, talk to your doctor about your questions and concerns. He or she can explain how the surgery might benefit you and help put the risks in perspective. Your doctor will discuss with you whether you're a candidate for the procedure.