Regression After Smile Surgery

What Is Regression After SMILE Surgery?

Regression refers to a partial return of your original refractive error — typically myopia (shortsightedness) — after laser vision correction. It doesn’t mean the cornea has “grown back” to its original shape. Rather, biological healing responses or natural eye changes gradually shift the cornea’s curvature enough to reintroduce a small amount of blur. In clinical terms, a patient who was corrected to zero might drift back to –0.50 or –0.75 dioptres over the months or years following surgery.

It’s important to distinguish regression from normal post-operative fluctuations. In the first one to three months after SMILE, mild vision fluctuation is expected as the cornea stabilises. True regression is a sustained shift that persists beyond the stabilisation window, typically identified at the six-month or one-year follow-up. If you’re still in the early weeks and experiencing temporary blur, our guide on blurry vision after SMILE explains what’s normal and what warrants a call to your surgeon.

Why Does Regression Happen?

Epithelial Remodelling

The corneal epithelium — the outermost layer of cells — tends to thicken slightly after refractive surgery in response to the new corneal curvature. This compensatory thickening can partially offset the laser correction, effectively adding back a fraction of the original prescription. The process is gradual and often stabilises within the first year.

Stromal Healing Response

SMILE works on the stromal layer of the cornea. After lenticule extraction, the stroma undergoes a wound-healing response that can subtly alter the corneal contour. In most patients this is negligible, but in those with aggressive healing responses — or with higher initial corrections — the effect can be clinically meaningful.

Natural Myopia Progression

SMILE corrects your current prescription at the time of surgery. It does not freeze your eye’s refractive status permanently. If the underlying axial length of the eye continues to increase — which happens more commonly in younger patients — new myopia develops independently of the surgical correction. This is technically progression rather than regression, but to the patient it feels the same: blur that wasn’t there before. Understanding the broader causes of post-surgical regression helps frame SMILE-specific regression in context.

Who Is Most at Risk?

High Myopia Patients

Patients with prescriptions above –6 dioptres face a statistically higher chance of some regression. The greater the amount of tissue removed, the more aggressive the cornea’s healing response tends to be. If you had a prescription near SMILE’s upper treatment range (–10 D), your surgeon should have discussed this risk during your pre-operative assessment.

Younger Patients

Patients in their late teens or early twenties may still be experiencing natural myopic progression. This is why most surgeons require a stable prescription for at least 12 months before approving SMILE. Our page on the minimum age for SMILE surgery explains the stability requirements in detail.

Genetic and Lifestyle Factors

A strong family history of progressive myopia, excessive close-range screen work, and insufficient time spent outdoors have all been associated with ongoing myopic shift. While these factors don’t cause surgical regression per se, they contribute to new myopia that accumulates on top of any biological regression.

How Much Regression Is Normal?

Most published studies on SMILE report that the vast majority of patients maintain excellent long-term results. When regression does occur, it’s typically mild — in the range of –0.25 to –0.50 D — and often not noticeable in daily life. Clinically significant regression, defined as a shift of –1.00 D or more that impacts visual function, occurs in a small minority of cases. At Visual Aids Centre, we track every patient’s refraction at regular follow-ups — one day, one week, one month, three months, six months, and one year — precisely so that any drift is caught early and addressed before it becomes a problem.

Signs That Your Vision May Be Regressing

Regression tends to be gradual, so you may not notice it immediately. Watch for difficulty reading road signs at night, increased squinting when viewing distant text, eye strain during prolonged driving, or a general sense that objects in the distance aren’t as sharp as they were a few months after surgery. If you notice these symptoms, schedule a refraction check rather than assuming it’s just dry eyes — while dryness can temporarily blur vision, persistent distance blur at six months or beyond warrants a proper assessment.

How to Reduce the Risk of Regression

While you can’t fully eliminate biological healing responses, several evidence-based strategies help minimise regression risk. First, ensure your prescription was genuinely stable before surgery — at least 12 months of no change. Second, follow your post-operative care protocol precisely: use prescribed eye drops after SMILE surgery for the full recommended duration, as steroid drops in particular help modulate the healing response. Third, attend every scheduled follow-up so your surgeon can detect any subtle drift early. Finally, manage your screen habits — the 20-20-20 rule (every 20 minutes, look at something 20 feet away for 20 seconds) reduces accommodative strain that can contribute to myopic shift over time.

Treatment Options If Regression Occurs

Wait and Monitor

For minor regression (under –0.50 D), your ophthalmologist may recommend monitoring rather than immediate intervention. Vision at this level is often still functional without glasses, and the shift may stabilise on its own within a few months.

Enhancement Surgery

When regression is significant enough to affect daily life, an enhancement procedure can restore clear vision. The approach depends on your corneal thickness and anatomy. One common option is the “Circle” technique, which converts the SMILE cap into a flap and allows a LASIK-style excimer laser retreatment. Alternatively, a surface ablation procedure like PRK can be performed over the existing SMILE correction. Your surgeon at Visual Aids Centre will evaluate your residual corneal thickness, corneal topography, and overall eye health before recommending the best path. For a broader look at how enhancement fits into the refractive surgery landscape, our article on preventing regression after laser eye surgery covers complementary strategies.

Prescription Glasses or Contact Lenses

If enhancement isn’t suitable — perhaps due to insufficient residual corneal thickness — thin prescription glasses or contact lenses can correct the residual error. This isn’t a “failure” of the original surgery; even a small residual prescription after SMILE still leaves you dramatically less dependent on correction than before.