SMILE can significantly reduce myopia and dependence on glasses or contact lenses, but the correction is not necessarily permanent in exactly the same form for every patient. In some people, a small amount of myopia may return over time. This is generally described as myopic regression.
Regression does not necessarily mean that the SMILE procedure has failed. Small changes in refraction can occur after refractive surgery, and long-term studies have found that many patients continue to have good visual outcomes years after treatment.
If you are considering SMILE eye surgery, understanding why myopia can appear to return and what it means for your long-term vision can help you have realistic expectations about the procedure.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Can Myopia Really Come Back After SMILE?
Yes, some degree of myopic regression can occur after SMILE. However, the amount is usually small, and it does not happen to everyone.
Long-term studies have followed patients for five, seven, and even ten years after SMILE. These studies have generally found good stability of vision, while also detecting small average shifts toward myopia over time.
For example, a 10-year study of patients treated for myopia of up to -10.00 D found an average regression of approximately -0.32 D over the follow-up period. Another seven-year study of high-myopia patients reported average regression of approximately -0.34 D.
These averages do not mean that every patient will experience the same change. Some people remain very close to their intended correction for many years, while others may develop a more noticeable residual prescription.
What Does Myopic Regression Mean?
Myopic regression means that the eye gradually shifts toward a more myopic refractive state after the initial correction.
For example, imagine that your intended postoperative prescription is close to zero. If a later eye examination shows a prescription of -0.50 D, you have experienced a small shift toward myopia.
This is different from saying that the original level of myopia has completely returned. A small amount of regression may have little effect on everyday vision, while a larger change may make glasses useful again for certain activities.
How Soon Can Myopia Return After SMILE?
There is no fixed point at which myopia returns after SMILE. Some refractive changes may occur during the early healing period as the cornea stabilizes. Other changes may develop gradually over several years.
Long-term studies suggest that the refractive result after SMILE can remain relatively stable, although small shifts toward myopia may be detected during extended follow-up. This means that a patient can have excellent vision for years and still experience a modest change later.
A change in prescription shortly after surgery should also not automatically be interpreted as long-term regression. Early visual fluctuations can be related to healing, tear-film changes, or temporary refractive variation.
Why Can Myopia Return After SMILE?
There is no single explanation for every case of postoperative myopic regression. Several factors may contribute.
Changes in the cornea
SMILE changes the shape of the cornea to correct the original refractive error. Small structural and biomechanical changes can continue to occur as the cornea settles after surgery.
Long-term studies have generally found good corneal stability after SMILE, but subtle changes in corneal refractive power may contribute to some refractive shifts.
Higher original myopia
People who start with higher levels of myopia may experience more regression than those treated for lower prescriptions. Some long-term studies of high myopia have documented a measurable shift toward myopia over several years.
This does not mean that high-myopia patients cannot have stable results. Rather, the original prescription is one of the factors that may influence long-term refractive stability.
Natural changes in the eye
Refractive error can change naturally with age. Not every increase in myopia after SMILE is necessarily caused by the surgery itself.
This distinction is important when evaluating a prescription years after treatment. Your eye specialist may compare current measurements with previous examinations to determine whether the change is consistent with postoperative regression or another refractive change.
Individual healing response
People do not all heal in exactly the same way after refractive surgery. Differences in corneal characteristics, prescription, age, and other eye-related factors can influence the final refractive result.
How Much Myopia Can Return After SMILE?
There is no single amount that can be expected for every patient. Published long-term studies have generally found relatively small average changes.
One five-year study of moderate myopia found an average difference from the intended correction of approximately -0.13 D. A separate study involving a broader range of myopia found approximately 0.19 D of myopic regression at long-term follow-up.
In patients with high myopia, larger shifts can occur in a minority of cases. One five-year study involving high myopia found that 59% of eyes were within ±0.50 D of the intended correction and 92% were within ±1.00 D at five years.
These findings illustrate why individual results can differ considerably from the average. A small residual prescription may not be noticeable, while a larger change can affect distance vision.
What If My Vision Becomes Blurry After Being Clear for Years?
If your vision becomes blurry after a long period of good vision, it is worth having your eyes examined rather than assuming that myopia has returned. The examination can determine whether the change is related to:
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
- Myopic regression
- Residual or new astigmatism
- Dry eye or tear-film instability
- Changes in the cornea
- Another eye condition
- Natural changes in refractive error
The Bottom Line
Myopia can return to some degree after SMILE, but this does not mean that the original myopia has necessarily returned or that the surgery has failed. Long-term studies generally show good visual and refractive stability, while also demonstrating that small shifts toward myopia can occur over several years.
The amount of regression varies from person to person. Higher preoperative myopia may be associated with greater regression in some patients, but individual healing and other eye characteristics also matter.
If your vision becomes less clear after SMILE, an eye examination is the best way to determine whether the change represents myopic regression or another cause of blurred vision. In selected cases, an enhancement procedure may be considered, while a small residual prescription may simply be monitored or corrected with glasses when needed.
Overall, SMILE can provide long-lasting reduction in myopia for many patients, but it is more realistic to think of the result as a durable refractive correction rather than a guarantee that your prescription will never change again.
