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LASIK Overcorrection and Undercorrection

Two of the most common LASIK complications are overcorrection and undercorrection. If you experience one of these conditions, it means that you still have some degree of a refractive error following your surgery.

Overcorrections and undercorrections are rarely the result of an error by your ophthalmologist or a defect in the laser. They are generally caused by differences in the way each person’s eyes heal following surgery.

In general, overcorrection most commonly occurs with people who are slow healers, while aggressive healers are more likely to experience undercorrection.

Am I at Risk of Overcorrection or Undercorrection?

The patients most at risk of overcorrection or undercorrection are those who have very high prescriptions. For example, if your prescription before LASIK surgery was -10.00 diopters and you experience a 10% undercorrection, your post-surgery prescription will be -1.00 diopters, or roughly 20/40 vision. As a result, you may find that you still experience enough nearsightedness to cause blurry vision.

If, however, your initial prescription before surgery was only -1.00 diopters, then a 10% undercorrection will leave you with a post-surgery prescription of -0.10 diopters, which will most likely not affect your vision at all.

During your initial evaluation, your eye surgeon should be able to inform you as to whether or not your prescription will make you prone to overcorrection or undercorrection. If you are at risk for these complications, you may want to think carefully about whether or not LASIK is right for you.

Treatment for Overcorrection or Undercorrection

Usually, overcorrection and undercorrection can be treated with an enhancement procedure. However, if your corneas are either too steep or too thin, you may not be able to undergo an enhancement procedure. Your eye surgeon should warn you of this before performing the initial surgery so that you can factor this information into your decision to have LASIK.

Please contact an eye doctor in your area if you are interested in LASIK surgery.

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