If you have a refractive error, such as nearsightedness (myopia), farsightedness (hyperopia), astigmatism or presbyopia, refractive surgery is a method for correcting or improving your vision. This surgical procedure is used to adjust your eye’s focusing ability by reshaping the cornea, or clear, round dome at the front of the eye. The most widely performed type of refractive surgery is LASIK (laser-assisted in situ keratomileusis), where a laser is used to reshape the cornea.
Refractive surgery might be a good option for you if you:
- Want to decrease your dependence on glasses or contact lenses
- Are free of eye disease
- Accept the inherent risks and potential side effects of the procedure
- Understand that you could still need glasses or contacts after the procedure to achieve your best vision
- Have an appropriate refractive error
With LASIK, a surgeon creates a thin flap in the cornea using either a blade or a laser. The surgeon folds back the flap and precisely removes a very specific amount of corneal tissue under the flap using an excimer laser. The flap is then laid back into its original position where it heals in place.
For people who are nearsighted, LASIK is used to flatten a cornea that is too steep. Farsighted people will have LASIK to achieve a steeper cornea. LASIK can also correct astigmatism by shaping an irregular cornea into a more normal shape.
It is important that anyone considering LASIK have realistic expectations. LASIK allows people to perform most of their everyday tasks without corrective lenses. However, people looking for perfect vision without glasses or contacts run the risk of being disappointed. More than 90 percent of people who have LASIK achieve somewhere between 20/20 and 20/40 vision without glasses or contact lenses. If sharp, detailed 20/20 vision is essential for your job or leisure activities, consider whether 20/40 vision would be good enough for you.
You should be comfortable with the possibility that you may need a second surgery (called a retreatment or enhancement) or that you might need to wear glasses for certain activities, such as reading or driving at night. Also, you should be aware that LASIK cannot correct presbyopia, the age-related loss of close-up focusing power.
LASIK Risks and Side Effects
LASIK, like any surgery, has potential risks and complications that should be carefully considered. LASIK has now been performed on millions of patients in the United States for more than 10 years, and the overall complication rate is low, between 0.2 and 2 percent of all patients. Infection and inflammation are possibilities, as with any surgical procedure, and usually can be cleared up with medications.
Problems with the corneal flap after surgery sometimes make further treatment necessary. There is a chance, though small, that vision will not be as good after the surgery as before, even with glasses or contacts.
Some people experience side effects after LASIK that usually disappear over time. These side effects may include hazy or blurry vision; difficulty with night vision and/or driving at night; scratchiness, dryness and other symptoms of the condition called “dry eye”; glare, halos or starbursts around lights; light sensitivity; discomfort or pain; or small pink or red patches on the white of the eye. In a small minority of patients, some of these effects may be permanent.
Sometimes a second surgery, called a retreatment or enhancement, may be needed to achieve the desired vision correction. This is more likely for people who were more nearsighted, farsighted, or had higher astigmatism before LASIK — those whose vision originally needed more intensive correction. Approximately 10.5 percent of LASIK patients in the United States require a retreatment.
Before choosing to have LASIK, it’s important to do your homework to ensure you are a good candidate, understand the potential risks and benefits, and have realistic expectations about what your vision will be like after surgery and for years to come.