LASIK , which stands for laser in-situ keratomileusis, is generally a safe and effective procedure for many common vision problems. However, not everyone with a vision disorder is a good candidate for this procedure. The Eye Surgery Education Council (ESEC) has developed guidelines to determine who is a good candidate and to explain what you can expect if you have the surgery.

LASIK is performed by an ophthalmologist, a medical doctor specializing in the eye. It is a quick and relatively painless procedure in which a laser is used to permanently change the shape of the cornea. The cornea is the clear covering over the front of the eye. After surgery, most people have improved vision and no longer need glasses or contact lenses. However, this procedure is not for everyone, and it is important to have realistic expectations of the outcome.

Are You A Good Candidate?

The ESEC outlines specific criteria that put people into one of three categories:

The Ideal LASIK Candidate

Characteristics of the ideal LASIK candidate include:

  • Over age 18 and has had a stable glasses or contact lens prescription for at least two years
  • Has enough corneal thickness to allow the surgeon to safely create a corneal flap
  • Has one or a combination of these common vision problems:
  • Does not have any disease, vision-related or otherwise, that may reduce the effectiveness of the surgery or the ability of the eye to heal properly
  • Is well informed about the benefits and risks of LASIK

The "Less Than Ideal" LASIK Candidate

There are factors that preclude someone from being an ideal candidate. However, if you discuss the risks and benefits extensively with your doctor and set realistic expectations, you could still have the surgery. Factors that make someone a "less than ideal" candidate include:

  • Having a history of dry eyes (may worsen after LASIK)
  • Taking medications (eg, steroids or immunosuppressants) that can prevent healing
  • Having an autoimmune disorder or other condition that slows healing
  • Scarring of the cornea

There are also temporary factors that keep someone from being an ideal candidate. Once these factors change, surgery may be possible. These include:

  • Age under 18
  • Unstable vision, which usually occurs in young people; when vision has been stable for 2 years, surgery is possible
  • Pregnancy or breastfeeding
  • History of ocular herpes within the past year; once a year has passed since initial diagnosis, surgery can be done

The Non-LASIK Candidate

Having certain diseases completely precludes a person from having the LASIK procedure. These include:

  • Cataracts
  • Advanced glaucoma
  • Corneal diseases
  • Corneal thinning disorders
  • Other pre-existing eye disorders that affect or threaten vision

Screening Before LASIK

If you are considering LASIK, schedule an appointment with an eye care professional. You will need a thorough eye exam, as well as a consultation with a doctor. The results of the exam can help the doctor determine if you are a candidate for the surgery and what type of success you can expect.

What to Expect

For the majority of people, LASIK improves vision and reduces the need for glasses or contact lenses. However, there are some risks to be aware of. These include:

  • Re-treatments may be necessary to achieve optimal results. Even after re-treatment, though, vision may not be as good after LASIK, as it was with glasses or contact lenses before the surgery.
  • After the procedure, there may be visual aberrations, such as glare and halos under dim lighting conditions. In most cases, these aberrations are minor and will resolve with time. However, in some cases, they can be severe enough to interfere with daily life.
  • LASIK will not cure presbyopia , which is the age-associated eye changes that prevent older people from seeing near objects through the same glasses they use for viewing distant objects. However, a technique called monovision may be done. In this case, one eye is corrected for distance vision, and the other is left nearsighted to allow focusing on near objects without glasses.
  • Like all surgical procedures, there is a risk of serious complications. For LASIK, this risk is small—in the many millions of procedures done so far, less than 1% of patients have experienced serious, vision-threatening problems. Most complications that occur can delay full recovery time, but resolve within several months of the surgery.