What Is SMILE Pro? A Complete Guide to SMILE Eye Surgery

SMILE Pro belongs to a family of procedures that all do the same thing by different routes: they change the curvature of the cornea so that light focuses on the retina instead of in front of it. What makes SMILE different from LASIK and PRK is not the goal but the method, and understanding that difference explains almost everything else: why there is no flap, why recovery looks the way it does, and why not everyone is a candidate.

What does SMILE actually stand for?

SMILE is an acronym for small incision lenticule extraction. Both halves of that name describe the procedure literally. A lenticule is a small, lens-shaped piece of corneal tissue. The small incision is the opening (measured in millimetres rather than in the centimetres of a LASIK flap) through which that lenticule is pulled out.

The formal term you will see in the medical literature is refractive lenticule extraction, sometimes abbreviated ReLEx SMILE, which is the name the manufacturer originally used for the technique.

How does SMILE Pro work, step by step?

A femtosecond laser is focused inside the cornea. It creates two surfaces (the front and back faces of the lenticule) which together define a disc of tissue of a precisely chosen shape and thickness. It then creates a short arc-shaped incision at the edge of the cornea.

The surgeon separates the lenticule from the surrounding tissue with a fine instrument and draws it out through the incision. Removing that disc changes the shape of the cornea, which changes how it bends light.

Because the laser works inside the cornea rather than on its surface, and because the incision is small, the outer layer of the cornea is largely left intact. That single design choice is the source of most of the differences people ask about.

Where does the “Pro” come from?

“SMILE Pro” refers to the generation of the procedure performed on the ZEISS VISUMAX 800 laser platform. Earlier SMILE was performed on the VISUMAX 500. The 800 generation brought a faster laser application and assistance features aimed at centration and astigmatism alignment, which the manufacturer describes on its product pages.

Two things are worth being careful about here. The first is that “Pro” is a naming convention, not a clinical guarantee: a clinic offering SMILE on an older platform is still offering SMILE, and the difference between generations is a matter of technique and workflow rather than a different operation. The second is that manufacturer material is not independent evidence. Where we describe platform features, we say so and link to the source rather than presenting it as an established clinical advantage.

Why is there no excimer laser?

This is the detail that most surprises people who have read about LASIK. A LASIK procedure uses two lasers: a femtosecond laser to create the flap, and an excimer laser to remove tissue from the exposed surface underneath.

SMILE uses only the femtosecond laser. The tissue that would have been ablated by the excimer is instead cut out as a solid lenticule and removed. There is no second laser, no surface ablation, and no flap.

That does not make SMILE better. It makes it different, and the differences show up in specific places: how the cornea’s surface nerves are affected, how the eye feels in the days afterwards, and what the surgeon is able to adjust during the procedure itself. Those trade-offs are set out side by side on our comparison page.

What does SMILE Pro treat?

SMILE is used to correct short-sightedness (myopia) and, in the same procedure, the astigmatism that frequently accompanies it. Long-sightedness (hyperopia) is a different situation: hyperopic correction is not offered with SMILE in every market, and where it is, the criteria are narrower.

Whether any of that applies to you is a question about your measurements rather than your symptoms. Two people with the same prescription can get different answers, because prescription is only one of several inputs. We explain the rest in who is eligible for SMILE Pro.

What does the recovery look like?

Most people notice a marked improvement in vision within the first day, and functional vision (enough to work, read and use a phone) usually returns quickly. It is not instant and it is not uniform. Vision often fluctuates for the first days and weeks, dryness is common, and night vision can take longer to settle.

Vision that is good enough to read a chart is not the same as vision that is comfortable all day. Our recovery guide describes the difference, and the timeline article sets out what tends to happen when.

What are the risks?

Every refractive procedure carries the same categories of risk, because they come from reshaping a cornea rather than from the specific technique: dry eye, glare and halos, temporary fluctuation, under- or over-correction, residual prescription, and (rarely) infection or inflammation. Enhancements are sometimes needed later.

What differs between procedures is the frequency and character of those risks in a given patient, and that is exactly the judgement a surgeon makes during assessment. Our risks page covers them without dressing them up.

What this means for you

If you are short-sighted, SMILE Pro is one of the options worth asking about, but “worth asking about” is the whole of its status before an examination. Nothing on this page, and nothing on any website, can tell you whether your cornea has the thickness, shape and surface quality for it.

Use this article to learn the vocabulary, then use the procedure page to see what actually happens on the day and the eligibility guide to see what will be measured. Take both to your consultation. Questions asked in the right terms get much better answers than questions starting from scratch.