Can the Smile Pro Procedure Be Repeated?

What “Repeat” Actually Means After SMILE Pro

The word “repeat” carries different meanings depending on what the patient is asking. If the question is can the same eye be treated twice for refractive correction, the answer is yes — enhancement procedures exist and are routinely performed. If the question is can the same SMILE Pro lenticule-extraction technique be used twice on the same eye, the answer is rarely and with significant caveats. And if the question is can both eyes have SMILE Pro done (in the same patient), the answer is trivially yes — in fact, most patients have bilateral surgery in the same session. Our article on whether SMILE Pro can be performed on both eyes covers the bilateral-surgery question in detail.

The interesting case is the single eye that needs additional correction after its first SMILE Pro. This is what the clinical literature calls “enhancement” or “re-treatment.” Importantly — and contrary to what many online articles suggest — SMILE Pro is a flapless procedure. It does not create a corneal flap the way LASIK does. So the idea of “lifting the flap and repeating SMILE Pro” isn’t how SMILE Pro works, since there is no flap to lift.

Why Enhancement Is Rarely Needed

Modern SMILE Pro, performed on the ZEISS VisuMax 800 platform, is remarkably accurate. Roughly 95% of well-selected patients reach 20/20 vision or very close to it without ever needing a second procedure. The enhancement rate — the percentage of patients needing any kind of re-treatment after their first SMILE Pro — sits in the 2–5% range in most published series, lower than typical enhancement rates for LASIK done on comparable refractive errors.

When enhancement is needed, it’s almost always for small residual refractive error (less than 1 dioptre of myopia or astigmatism remaining) that affects comfort for specific tasks like long-distance driving or fine near work. The majority of enhancement cases are patients who started with very high initial prescriptions (above -7.00 dioptres), where even minor variability in surgical response produces noticeable residual.

When Enhancement Becomes a Real Option

A second procedure is reasonable to consider when three conditions are met:

• Stable residual refraction. The refraction must be stable across at least two consecutive examinations, ideally 4–6 weeks apart. Early fluctuation during the first few months is normal and not a reason for enhancement.
• Minimum 3–6 month interval. Enhancement before the cornea has fully healed from the initial surgery adds unnecessary risk. Most surgeons wait a minimum of 3 months, and some wait 6.
• Clinically meaningful residual. A residual of -0.50 dioptre may be annoying but is often not worth re-operating for. Residuals beyond -0.75 to -1.00 dioptre are more often addressed.

If your refractive correction has genuinely regressed (the power has drifted over time rather than being residual from day one), the calculus is different. See our article on whether your number can come back after SMILE Pro for that specific scenario.

Which Technique Is Used for the Re-treatment

This is where SMILE Pro differs from LASIK in an important way. After LASIK, enhancement is often a second LASIK — the surgeon lifts the original flap, applies additional excimer laser, and the eye is done. After SMILE Pro, the surgical options for enhancement are:

• Surface ablation (PRK or Trans-PRK). The most common choice. The surgeon gently removes the epithelium and applies a measured amount of excimer laser to the residual refractive error. No new flap, no new lenticule — just a precise surface re-sculpting. Recovery takes 5–7 days for the epithelium to regenerate.
• Femto-LASIK over the SMILE Pro cornea. Rarely used, because creating a LASIK flap on top of a previously operated cornea carries its own complications.
• A second SMILE Pro lenticule. Technically feasible in specific cases but not routinely recommended. Most surgeons prefer surface ablation.

The standard answer for almost all SMILE Pro enhancement cases is PRK. This is why the question “can SMILE Pro be repeated” is better answered as “yes, but usually with a different technique.” For the broader context on how SMILE Pro compares with PRK as a primary procedure, see whether SMILE Pro is better than PRK.

The Corneal Tissue Budget

Every refractive procedure removes a measured amount of corneal stromal tissue. SMILE Pro extracts roughly 10–15 microns per dioptre of correction, which translates into 70–120 microns for moderate-to-high myopia. A normal cornea starts at around 520–550 microns thick, and surgeons aim to leave at least 300 microns of residual stromal bed after any procedure to maintain long-term structural stability.

This means the amount of tissue available for enhancement depends entirely on what was consumed by the first procedure. A patient treated for -2.00 dioptre myopia has plenty of tissue in reserve for a small enhancement years later. A patient treated for -9.00 dioptre myopia may have almost no margin left. This is the single biggest reason surgeons are cautious about enhancement — not because the second procedure is risky in isolation, but because the cornea’s tissue budget may not permit it safely. Our article on how much cornea is removed in SMILE Pro surgery covers the specific measurements.

Real Risks of a Second Procedure

Any refractive enhancement carries incremental risk:

• Corneal ectasia. The most serious concern — progressive corneal thinning and bulging. Risk rises if residual stromal bed drops below safe thresholds after enhancement.
• Corneal haze. A cloudiness of the cornea that can follow surface ablation, more likely after multiple procedures. Modern mitomycin-C application during PRK has reduced but not eliminated this risk.
• Infection. Low absolute risk, but present with any surgical intervention on the eye.
• Dry eye exacerbation. SMILE Pro causes less dry eye than LASIK, but any additional procedure on an already-operated cornea extends the period of transient dryness.
• Over- or under-correction. Predicting refractive response after a first procedure is slightly harder than predicting a primary treatment. A second residual is possible, though usually smaller.