Is SMILE Pro Safer Than LASIK? What the Evidence Actually Shows

One of the most common questions patients ask in our Newport Beach consultations is whether SMILE Pro is safer than LASIK. It is a reasonable question. SMILE Pro is newer, it is flapless, and much of the marketing around it leans heavily on the idea that avoiding a LASIK flap means avoiding risk.

The honest answer is more nuanced than the marketing. By every meaningful clinical safety metric, modern LASIK and SMILE Pro are both extraordinarily safe procedures. The real question is not which procedure is safer but which type of risk are you most concerned about, and which procedure produces the best overall visual outcome.

Here is what the current evidence actually shows.

The Short Answer

Both WaveLight® Plus LASIK and SMILE Pro have safety indices at or near 1.00 in peer-reviewed studies, meaning virtually no patient loses clinically meaningful best-corrected vision from either procedure. The clinical difference between the two is not in safety in the traditional sense. It is in visual quality, precision, and the type of rare complications each procedure can produce.

If your definition of safer includes the quality of vision you end up with, the evidence currently favors WaveLight® Plus LASIK. If your definition of safer is strictly about avoiding a corneal flap, SMILE Pro has a structural argument, but as we cover below, it is not the only flapless option, and it is not the one we recommend. Both things can be true at the same time.

Five Ways to Define Safety in Refractive Surgery

When patients ask about safety, they are usually blending five different concerns. It helps to separate them.

1. Loss of Corrected Vision

The strictest definition of safety in refractive surgery is the safety index: the ratio of postoperative best-corrected distance visual acuity to preoperative best-corrected distance visual acuity. A safety index of 1.00 means patients, on average, see just as sharply with glasses after surgery as they did before.

Modern SMILE Pro studies consistently report safety indices of 1.00. A large 2025 study of 765 eyes using the VisuMax 800 platform found that 99.47% of eyes had no change in corrected distance visual acuity at three months, with zero postoperative complications. WaveLight® Plus LASIK reports the same pattern: in the published WaveLight® Plus clinical study (He C, Bala C. J Cataract Refract Surg. 2023;49(11):1140-1146), 100% of eyes achieved 20/20 or better uncorrected, and no eyes lost two or more lines of best-corrected vision.

Verdict: Clinically identical. Both procedures are exceptionally safe on this measure.

2. Flap-Related Complications

This is where SMILE Pro’s structural advantage is real. LASIK creates a thin corneal flap that is lifted during surgery and re-floated into place afterward. The flap heals strongly but never truly becomes one contiguous piece of cornea again. In rare cases, typically from significant eye trauma, a flap can be dislodged even years after surgery.

SMILE Pro does not create a flap. The procedure extracts a small lens-shaped piece of corneal tissue through a 2 to 4 mm incision, leaving the anterior cornea essentially intact. There is no flap to dislodge.

For active-duty military, MMA fighters and other combat athletes, and patients whose occupations or hobbies carry a real risk of direct eye trauma, avoiding a flap is a legitimate consideration. Our position on those patients differs from the SMILE Pro marketing: at Feinerman Vision, Dr. Feinerman typically recommends PRK for contact sports and high-trauma occupations, a surface treatment that involves no flap and no cap interface at all. For the vast majority of patients, flap dislocation is so rare with modern femtosecond bladeless LASIK that it does not drive the safety calculation in practice. The Ziemer Z8® femtosecond laser we use at Feinerman Vision creates flaps with predictable edge geometry and strong healing characteristics.

Verdict: A flapless approach is a fair preference for trauma-exposed patients, and PRK meets that need without a flap or a cap. For everyone else, the absolute flap risk with modern bladeless LASIK is already very low.

3. Dry Eye

LASIK disrupts corneal nerves during flap creation, which can temporarily reduce tear production. Advocates highlight SMILE Pro’s smaller incision, which preserves more corneal nerves in the short term, as a potential advantage: multiple meta-analyses have shown lower dry eye scores in SMILE patients for the first 3 to 6 months postoperative.

The catch: by 12 months, most studies show no significant difference between SMILE and LASIK in dry eye incidence or severity. Meta-analysis data show that corneal nerve metrics have not returned to preoperative levels at one year after either procedure. The early difference between the two shrinks as nerves regenerate, but neither corneal procedure leaves the ocular surface untouched. A long-term study of patients 5 to 15 years after surgery found significantly higher rates of tear hyperosmolarity, a marker of tear film instability, in laser vision correction patients than in non-surgical controls, while implantable collamer lens patients showed no difference from controls (Gjerdrum B, et al. Clin Ophthalmol. 2020;14:269-279).

That is why our position differs from the marketing here. SMILE Pro and LASIK both remove corneal tissue, so when the ocular surface is the concern, they are usually ruled out for the same reasons. When dry eye risk is meaningful, Dr. Feinerman typically recommends evaluation for EVO ICL™ instead: the lens is placed inside the eye, no corneal tissue is removed, and the corneal nerves are largely undisturbed, which is why EVO ICL™ carries a lower dry eye impact than LASIK. Patients with moderate-to-severe pre-existing dry eye are typically not candidates for either LASIK or SMILE Pro and should be evaluated for EVO ICL™ or surgical postponement until the dry eye is controlled.

Verdict: Any short-term difference between the two corneal procedures equalizes by 12 months, and neither is the right answer when the ocular surface is fragile. For meaningful dry eye risk, the practice position is EVO ICL™, which removes no corneal tissue at all.

4. Visual Quality and Optical Side Effects

This is the dimension where the recent head-to-head evidence favors WaveLight® Plus LASIK decisively, and it is the dimension most patients overlook when they ask about safety.

A procedure that produces 20/20 vision with significant night-driving glare, halos, starbursts, or reduced contrast sensitivity is not as safe in any practical sense as a procedure that produces the same visual acuity without those compromises. Optical side effects are a real form of postoperative harm.

The evidence base for ray-tracing has since deepened. In a randomized, double-masked, contralateral eye trial published in Ophthalmology, the journal of the American Academy of Ophthalmology, WaveLight® Plus was compared directly against wavefront-optimized LASIK, the current standard of care. The WaveLight® Plus ablation was planned entirely from objective measurements captured by the INNOVEYES SightMap™ device, with no manifest refraction, and achieved refractive accuracy equal to or slightly better than the conventionally planned eye (Khoramnia R, et al. Ophthalmology. 2025;132(10):1169-1179). A laser platform that can plan a treatment from direct measurement of the eye’s optics, without relying on the subjective better-one-or-better-two refraction, is measuring the eye more completely than any prior generation of LASIK.

Higher-order aberrations are the optical imperfections responsible for glare, halos, starbursts, and the complaint that vision is 20/20 but does not feel as sharp as glasses did. Lower higher-order aberrations mean a cleaner, crisper visual result, especially in low light. In the Kanellopoulos contralateral study, the WaveLight® Plus eyes came out ahead on exactly this measure, along with contrast sensitivity and astigmatism correction.

Verdict: Significant advantage to WaveLight® Plus LASIK, driven by its ray-tracing personalization, now documented in both a real-world published series and randomized contralateral trials.

5. Enhancement and Residual Refractive Error Safety

No refractive procedure hits the target perfectly 100% of the time. Enhancements (also called touch-ups) are how surgeons correct a small residual refractive error after the initial surgery. This is a real and often-overlooked safety dimension, and it is the area where LASIK and SMILE Pro differ the most.

Both modern procedures have low enhancement rates. Per data presented at AAO October 2025 (Venkateswaran, Mass Eye and Ear/Harvard), SMILE enhancement rates are under 4%. Modern LASIK enhancement rates are 1.45% per a 14-year academic series at Mass Eye and Ear, and a 2023 head-to-head study (Mathur et al., Indian Journal of Ophthalmology) reported nearly identical rates: 0.5% for SMILE versus 0.44% for LASIK. The marketing argument that “SMILE has lower enhancement rates” is no longer supported by modern data. Both procedures land in roughly the same 1% to 5% range across published series.

The clinically meaningful question is what happens when an enhancement is needed.

LASIK enhancement is straightforward. The original flap is gently lifted, the excimer laser fine-tunes the correction, and the flap is replaced. It uses the same technology and the same anatomy as the original procedure, and it works whether the residual error is myopia, hyperopia, or astigmatism. LASIK enhancement has been a standard, predictable procedure for more than two decades.

SMILE Pro enhancement is a different story. There is no equivalent to lifting a LASIK flap because SMILE Pro does not create one. When a SMILE Pro patient has a residual refractive error, the surgeon has four options, each with meaningful drawbacks:

1. PRK on top of the SMILE cap. The most common US approach. The surgeon removes the corneal epithelium and applies the excimer laser at the surface, always with mitomycin C to reduce the risk of haze. Recovery is slow and uncomfortable: patients describe days of pain and weeks of visual fluctuation, compared to hours for a LASIK flap-lift enhancement. Published series report approximately a 2.5% risk of postoperative corneal haze, even with mitomycin C.
2. Thin-flap LASIK above the SMILE plane. The surgeon creates a new LASIK flap (typically 90 to 100 µm) in the thin layer of cornea above the original SMILE lenticule cut. In the US, where SMILE Pro caps are locked at 120 µm, this leaves only 20 µm of stromal tissue between the two cut planes, far less than international markets where caps are typically 135 to 145 µm. Femtosecond laser tolerance compounds across two procedures: VisuMax cap thickness has a documented range of -11 to +14 µm relative to intended depth (Reinstein et al., Journal of Refractive Surgery), and other femtosecond platforms show standard deviations of 13.8 to 15.5 µm. In a plausible scenario, the original SMILE cap could cut at 105 µm and the enhancement flap at 115 µm, meaning the enhancement laser cuts deeper than the original cap. Buttonhole flap creation, tissue slivers, gas bubble breakthrough, and tissue bridge perforation can result, with permanent visual consequences.
3. Thick-flap LASIK below the SMILE plane. The surgeon creates a deeper flap (typically 140 to 160 µm) that incorporates the original SMILE lenticule plane within the new flap. A 2019 Journal of Refractive Surgery porcine eye biomechanical study found that LASIK enhancement of a SMILE cornea induced approximately 7% additional biomechanical weakening, while PRK and Re-SMILE enhancements did not. Corneal cross-linking can partially compensate, but it is an additional procedure with additional risks, high cost, and recovery time. This pathway is not appropriate for patients whose corneas are within the normal range but on the thinner side.
4. Cap-to-flap conversion with Zeiss CIRCLE software. This is the enhancement technique Zeiss officially designed for SMILE. It converts the original SMILE cap into a LASIK-style flap that can be lifted for excimer laser treatment. There is one significant problem: CIRCLE software is not approved or commercially available in the United States.

US surgeons who still want to perform cap-to-flap conversion use an off-label workaround called pseudo-Circle. The surgeon programs the VisuMax laser to create a LASIK flap, initiates suction, intentionally breaks suction partway through, then re-docks to complete only the vertical side cut, effectively “tricking the laser” into converting the existing SMILE cap into a LASIK flap. Pseudo-Circle carries additional risk because it lacks the vertical junction cut included in CIRCLE software, which can produce slightly incongruous tissue planes and tissue slivers at the cap-flap interface. Peer-reviewed literature describes this as off-label and notes that any form of surgical enhancement of a primary refractive procedure is off-label in the United States.

None of these SMILE Pro enhancement pathways carry the simplicity, safety record, or predictability of a standard LASIK flap-lift enhancement.

The hyperopia trap. SMILE Pro is FDA approved only for myopia and myopic astigmatism. If a SMILE Pro patient ends up overcorrected into hyperopia after surgery, the SMILE Pro laser cannot treat them at all. Their only options are PRK on top of the cap or an off-label flap-conversion enhancement. PRK for hyperopia is meaningfully worse than PRK for myopia: per a systematic review and meta-analysis in the Journal of Optometry (Hashemi et al.), hyperopic PRK has a 32.5% incidence of postoperative corneal haze, significantly higher than myopic PRK, due to the unique biology of peripheral corneal keratocytes that are removed during hyperopic ablation. Hyperopic PRK also shows higher regression and less stability. A LASIK patient in the same situation is treated with a standard hyperopic LASIK enhancement on the EX500 platform, which is FDA approved for the treatment of hyperopia.

At Feinerman Vision, all primary LASIK procedures (both Wavefront-Optimized LASIK and WaveLight® Plus LASIK) include lifetime enhancement coverage. Lifetime coverage is meaningful only if the enhancement procedure itself is straightforward.

Verdict: Significant advantage to LASIK.

For a complete deep-dive into SMILE Pro enhancement complexity, including all four pathways, the CIRCLE software gap, and the hyperopia trap, see SMILE Pro Enhancement: Why Touch-Ups Are More Complicated Than LASIK.

Why WaveLight® Plus Outperforms SMILE Pro on Visual Quality

The mechanism behind the Kanellopoulos findings is not a mystery. SMILE Pro uses a femtosecond laser to cut a pre-calculated lenticule shape, and that is essentially the extent of its customization. It is an elegant procedure, and its simplicity is part of its appeal. But it does not individualize treatment based on the specific higher-order aberration pattern of each eye.

WaveLight® Plus LASIK uses the INNOVEYES SightMap™ system to capture more than 100,000 data points from each eye, combining axial length measurements from interferometry, Scheimpflug tomography, and Hartmann-Shack wavefront analysis. It constructs a three-dimensional digital twin of the full optical system of the eye and uses ray-tracing to calculate an ablation profile that corrects sphere, cylinder, and higher-order aberrations simultaneously. The EX500 excimer laser then delivers that personalized treatment.

This is a fundamentally different philosophy. SMILE Pro asks what lenticule shape will correct this prescription. WaveLight® Plus asks what is the exact optical behavior of this individual eye, and what ablation pattern will deliver the sharpest possible vision across all light conditions.

What About Long-Term Safety and Ectasia?

Post-refractive ectasia (a progressive weakening and bulging of the cornea) is the most feared long-term complication of any corneal refractive surgery. It is rare with both modern LASIK and SMILE Pro, and the single most important predictor is appropriate patient screening before surgery.

A common claim is that SMILE Pro is safer because it preserves the anterior cornea and therefore the biomechanical strength of the eye. The theory is sound. The clinical reality is that post-SMILE ectasia has been documented in peer-reviewed case reports, including eyes with normal preoperative topography and no perceivable risk factors (Journal of Refractive Surgery Case Reports, 2022). Ectasia is possible after any procedure that removes corneal stromal tissue, and SMILE Pro and LASIK both remove corneal tissue.

This is also why the candidacy math does not change between the two procedures. A cornea too thin to support LASIK safely is also too thin to support SMILE Pro. Practices occasionally position SMILE Pro as the answer for patients turned away from LASIK; the tissue biology does not support that.

At Feinerman Vision, we screen every candidate with corneal topography, Scheimpflug tomography, pachymetry mapping, and epithelial thickness mapping. Patients with borderline or suspicious findings are not offered flap-based LASIK regardless of their prescription. The best long-term safety tool in refractive surgery is candidate selection, not the specific procedure.

Who Is a Candidate, and What I Recommend Instead

SMILE Pro is approved for myopia and myopic astigmatism only. It is not approved for hyperopia. Within that range, the patients usually pointed toward it are those who want a flapless procedure and are willing to trade some visual precision for that structural difference.

There is a more important point that SMILE Pro marketing tends to leave out. SMILE Pro and LASIK both remove corneal tissue. A cornea too thin to support LASIK safely is also too thin to support SMILE Pro. In practical terms, a patient who is not a LASIK candidate is generally not a SMILE Pro candidate either.

That is why my preference is WaveLight® Plus LASIK and EVO ICL™. For a good LASIK candidate, WaveLight® Plus delivers the visual quality and the straightforward enhancement pathway described above. For a patient who is not a LASIK candidate, EVO ICL or PRK is usually the better option, not SMILE Pro:

• Thin corneas: EVO ICL is generally the stronger choice, because it removes no corneal tissue at all. In some cases PRK is appropriate.
• Meaningful dry eye risk: EVO ICL, which creates no flap and leaves the corneal nerves largely undisturbed.
• Higher prescriptions: EVO ICL is FDA approved for nearsightedness from -3.00 to -20.00 diopters, with or without astigmatism, in patients 21 to 60, a far wider range than any corneal laser procedure can safely cover.
• Serious eye-trauma exposure, including MMA fighters and other combat and contact-sport athletes: PRK, a flapless surface treatment.

EVO ICL is not a consolation prize. It is a reversible procedure that preserves every future lens option, and in a 4-year comparative study of high myopes, EVO ICL eyes showed less spherical aberration and coma than SMILE eyes (BMC Ophthalmology, 2023). More than 4 million implantable collamer lenses have been sold worldwide, and among patients studied, the implantable collamer lens carries a 99.4% satisfaction rate.

Which of these fits you is a question for an examination, not an article. Candidacy depends on your corneal thickness and topography, your prescription, your tear film, and your visual goals.

When WaveLight® Plus LASIK Makes Sense

For most refractive candidates in Orange County, WaveLight® Plus LASIK is the procedure that delivers the best combination of visual outcome, precision, and recovery:

• Patients who want the sharpest possible vision, including the potential for better-than-20/20 outcomes
• Patients with complex prescriptions, significant astigmatism, or preoperative higher-order aberrations
• Patients who want the fastest visual recovery (most WaveLight® Plus patients see clearly the following day)
• Patients who want the benefits of personalized ray-tracing correction
• Patients who value lifetime enhancement coverage backed by a simple, predictable enhancement pathway

The Bottom Line

Is SMILE Pro safer than LASIK is the wrong question, because both procedures are already profoundly safe. The better question is which procedure will give me the best vision and the fewest long-term optical compromises, given my eyes and my lifestyle.

For most patients, the current evidence favors WaveLight® Plus LASIK. Its ray-tracing personalization produces sharper vision, lower higher-order aberrations, and better contrast sensitivity than SMILE Pro in randomized contralateral comparison, while maintaining the same excellent safety profile. The enhancement pathway if a touch-up is ever needed is also simpler, more predictable, and better supported by FDA-approved technology. Some patients are drawn to SMILE Pro’s flapless approach; at Feinerman Vision, that preference is usually better served by PRK for trauma-exposed patients, and by EVO ICL™ when dry eye, corneal thickness, or a high prescription is the concern.

The only way to know which procedure is right for your eyes is a full diagnostic workup. Feinerman Vision does not perform SMILE Pro. We perform the procedures the evidence supports: WaveLight® Plus LASIK, EVO ICL™, and PRK, and the recommendation is made from your individual measurements, not from which procedure a practice is most invested in promoting.

Book your evaluation with Dr. Feinerman: call (949) 631-4780 or visit FeinermanVision.com.

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Frequently Asked Questions

Is SMILE Pro FDA approved?
Yes. The VisuMax 800 platform used for SMILE Pro is FDA approved for the correction of myopia and myopic astigmatism. It is not approved for the treatment of hyperopia.

Is WaveLight® Plus LASIK safer than older generations of LASIK?
Yes. WaveLight® Plus LASIK uses bladeless flap creation, advanced eye-tracking, iris recognition for centration, and ray-tracing ablation that accounts for each eye’s individual optical behavior. Safety and precision are meaningfully higher than first- and second-generation LASIK platforms.

Does SMILE Pro cause less dry eye than LASIK?
In the first 3 to 6 months after surgery, most meta-analyses show lower dry eye scores in SMILE patients. By 12 months, most studies show no significant difference between SMILE and LASIK in dry eye incidence. Both procedures remove corneal tissue, and patients with moderate-to-severe pre-existing dry eye are typically not candidates for either. When dry eye risk is a meaningful concern, Dr. Feinerman typically recommends evaluation for EVO ICL™, which removes no corneal tissue and leaves the corneal nerves largely undisturbed.

Can SMILE Pro cause corneal ectasia?
Yes, though it is rare. Peer-reviewed case reports document post-SMILE ectasia, including in patients without classic preoperative risk factors. Any procedure that removes corneal tissue carries some residual ectasia risk. Careful preoperative screening is the most important safety factor for any refractive procedure.

Which procedure has better long-term data?
LASIK has approximately 25 years of clinical data across millions of procedures worldwide. SMILE has been performed since 2007, with SMILE Pro (VisuMax 800) in clinical use since approximately 2021. LASIK currently has the deeper long-term safety and stability record.

Why does WaveLight® Plus LASIK produce better visual quality than SMILE Pro?
WaveLight® Plus uses ray-tracing personalization based on more than 100,000 data points per eye, correcting higher-order aberrations simultaneously with sphere and cylinder. SMILE Pro femtosecond lenticule shape is pre-calculated and does not individualize to each eye’s full optical profile. This is the core reason for the difference in visual acuity, contrast sensitivity, and aberration outcomes documented in the Kanellopoulos 2025 study.

Why is a SMILE Pro enhancement more complicated than a LASIK enhancement?
A LASIK enhancement is performed by lifting the original corneal flap and applying the excimer laser, a standard and predictable procedure. SMILE Pro does not create a flap, so enhancement requires either PRK on top of the cap, creation of a new thin or thick LASIK flap, or tricking the laser to perform cap-to-flap conversion. All three carry significant risks. The Zeiss CIRCLE software designed for SMILE enhancement is not available in the United States. If a SMILE Pro patient ends up hyperopic after surgery, SMILE cannot treat hyperopia at all, and PRK for hyperopia carries a 32.5% haze rate per published meta-analysis.

What are modern enhancement rates for LASIK and SMILE Pro?
Modern enhancement rates for both procedures are approximately 1% to 5%. A 2023 head-to-head study (Mathur et al., Indian Journal of Ophthalmology) reported 0.44% for LASIK and 0.5% for SMILE. Mass Eye and Ear at Harvard Medical School reports a 14-year LASIK enhancement rate of 1.45% on the WaveLight EX500 platform used at Feinerman Vision. The older claim that SMILE has lower enhancement rates than LASIK is no longer supported by modern data.

Does Feinerman Vision perform SMILE Pro?
No. Feinerman Vision does not perform SMILE Pro. Dr. Feinerman was the first surgeon in Orange County and greater Los Angeles to offer WaveLight® Plus LASIK following FDA approval in 2025. After evaluating SMILE Pro against WaveLight® Plus LASIK, he concluded that the visual quality advantages of WaveLight® Plus ray-tracing combined with the simpler, more predictable enhancement pathway of LASIK make it the stronger choice for the vast majority of refractive candidates. A consultation at Feinerman Vision includes a full candidacy assessment for the procedures performed here, with a recommendation based on your individual measurements and visual goals. Patients weighing safety alongside value often also review the cost of WaveLight® Plus LASIK.

If I’m not a LASIK candidate, am I a SMILE Pro candidate?
Usually not. SMILE Pro and LASIK both remove corneal tissue. When LASIK is ruled out because the cornea is too thin, SMILE Pro is generally ruled out for the same reason. Two options are worth evaluating instead. EVO ICL removes no corneal tissue at all, which often makes it the better choice for thin corneas, higher prescriptions, and meaningful dry eye risk. PRK is a surface treatment that creates no flap. Which one fits depends on your corneal thickness and topography, your prescription, and your tear film, all of which are measured at your consultation.

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Related reading:

• SMILE vs. LASIK: Complete Comparison
• WaveLight® Plus LASIK Overview
• LASIK at Feinerman Vision
• WaveLight® Plus vs. SMILE Pro: LASIK Night Vision
• WaveLight® Plus LASIK Recovery: What to Expect
• SMILE Pro Recovery vs. LASIK Recovery: A Day-by-Day Comparison
• SMILE Pro Enhancement: Why Touch-Ups Are More Complicated Than LASIK