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LASIK Enhancement: When Is It Truly Needed?

Dagny Zhu, M.D.

Medically Reviewed by Dagny Zhu, M.D.

Fact Checked
6 sources cited

Last Updated

LASIK surgery has been available for about 20 years, and in that time, millions of people have undergone the minimally invasive procedure and received great results. However, in rare cases, a surgical problem could cause the need for LASIK enhancement, or a second LASIK procedure to improve on or correct the previous procedure.

There are several reasons that enhancements may be needed, including undercorrection of the vision problem, overcorrection that leads to eye strain, problems with the epithelial flap during the healing process, or an infection. While these complications are rare, a second surgery can improve them.

Some patients come back years after their surgery, rather than months, to ask for an enhancement. Their eyes are changing again, due to age or progression of their original refractive error, and they want to keep the convenience of their original LASIK correction.

There are different qualifications for this type of procedure, but someone with healthy eyes should be able to undergo a LASIK enhancement five or more years after their first procedure.

LASIK Surgery and LASIK Enhancement

LASIK is an elective surgical procedure that corrects some kinds of refractive errors, like farsightedness or nearsightedness, that involve misshapen corneas that move light into the wrong place in the eye, so the retina does not pick up images properly. While millions of people all over the world have undergone LASIK and are happy with the results, there is a small risk that the eyes may be undercorrected or overcorrected, requiring LASIK enhancement — a second surgery that corrects lingering issues from the first.

The human eye is an organ which reacts to light and pressure. As a sense organ, the mammalian eye allows vision. Human eyes help provide a three dimensional, moving image, normally coloured in daylight.

The human eye is an organ which reacts to light and pressure. As a sense organ, the mammalian eye allows vision. Human eyes help provide a three dimensional, moving image, normally coloured in daylight.

The most common causes of ongoing vision problems after LASIK include:

  • Undercorrection of the problem.
  • Overcorrection, leading to eye strain.
  • Residual or induced astigmatism.

Most often, people who were nearsighted and chose LASIK to correct this problem return, asking for LASIK enhancement to improve their distance vision. Undercorrection is the overall most common cause of return requests, and this tends to occur in people who had trouble seeing far-away objects clearly and expected to see them better after the procedure. Sometimes, vision continues to improve for months, so surgeons will not immediately enhance the previous procedure due to risks. Once some time has passed, LASIK enhancement is a common way to adjust lingering astigmatism or undercorrection errors.

When Is LASIK Enhancement Needed?

In 2007, retreatment rates for LASIK procedures were reported, depending on the literature, as between 3 and 37.9 percent. Reasons that people seek LASIK enhancement include:

  • Patient and/or surgeon expectations. In some cases, people are fine with a small amount of ongoing refractive problem as long as it does not impact their daily tasks. Pre- and post-operative counseling help to manage patient expectations that their vision will be perfect immediately. Healing time can be up to two or three months, so full vision correction may not be experienced for some time after the procedure, although a lot of visual acuity will return in the days after the procedure. If the patient expects perfect vision, they are more likely to seek enhancement; however, it is important to know that there are cases when a patient’s vision is just not corrected enough for them to perform daily tasks.
  • Stable refractive error. If the ongoing vision problem does not change after three months, then it is appropriate to seek LASIK enhancement because the original procedure did not fully correct the shape of the cornea.
  • Improper refraction/data entered. The laser is pre-programmed with information to shape the cornea properly, and if this is off, even slightly, an undercorrection or overcorrection can occur.
  • Problems with the flap: During LASIK, a flap of tissue is cut and put to the side, and corneal shaping then occurs with a laser. If the flap does not heal properly or becomes dislocated, the patient will not get returned visual acuity. Retreatment may be more complex in this instance, but it has helped many people experience improved healing in the second round. Cutting a new flap may be part of the procedure, which can make healing take longer, but it is more likely to improve vision.
  • Other healing complications. Epithelial ingrowth or melting of the flap during the procedure means that the person needs to be retreated with LASIK enhancement. Essentially, this is because the surgery did not correct the error or caused a secondary error, which may be corrected with enhancement.

Modern LASIK Enhancements: A Changing Culture

As LASIK technology improves, errors during or after the procedure are less frequently reasons for patients to return for an enhancement. Instead, people liked the convenience of the original procedure so much that, they want to essentially “re-up” their original procedure as their corneas are changing again. More patients are coming back after 5 or 10 years because of natural corneal changes from age or progressing refractive errors leading them to need corrective wear again.

In many cases, these individuals are qualified for an enhancement procedure. As long as there is not a new or different condition like glaucoma or cataracts, a too-thin cornea, or other eye risks from the previous procedure, they should be able to undergo the procedure again. Their expectations need to be managed, especially if the eyesight changes are related to age. LASIK is a great tool for improving vision, but it does not cure all refractive errors.

Surgeons performing an eye surgery under the microscope at the hospital - healthcare and medicine concepts

For people who return years, rather than months, after their previous LASIK procedure, it is important that they have two acuity measurements performed three to six months after the enhancement to ensure that corneal changes are not beginning again, which can occur in age-related farsightedness.

Fortunately for anyone who needs or wants an enhancement, complications are either as common or less likely than in the first procedure. One study found that post-operative dry eye was less likely to occur from the enhancement procedure than in the first LASIK procedure.

Make sure that your surgical contract includes information about enhancements and how you can pursue treatment. Several eye surgeons will provide free enhancements within a certain period of time because they want to correct surgical errors.

It is important to know that your vision can fluctuate in the first months after surgery, and this does not automatically mean that your surgery did not take. If you still experience vision issues after six months and your eye has healed, you may be eligible for an enhancement to improve your vision further.


  1. Management of Unsuccessful LASIK Surgery. (2007). Comprehensive Ophthalmological Update.
  2. Refractive Surgery Enhancements. (January 20, 2015). EyeWiki: American Academy of Ophthalmology (AAO).
  3. LASIK Enhancement Success Relies on Timing. (February 1, 2001). Ocular Surgery News U.S. Edition. Healio: Ocular Surgery News.
  4. How to Approach LASIK Enhancements. (October 6, 2014). Review of Ophthalmology.
  5. Dry Eye After LASIK Enhancement. (2007). Comprehensive Ophthalmological Update.
  6. Lasik Eye Surgery. (February 2013). Consumer Reports.

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