SMILE is the standard-bearer for lenticule extraction surgeries, but others are emerging on platforms available outside the US at the moment and will likely be introduced here in the coming years.

SMILE is the standard-bearer for lenticule extraction surgeries, but others are emerging on platforms available outside the US at the moment and will likely be introduced here in the coming years. Photo: Bobby Saenz, OD, Anthony Vanrachack, OD, and Alexandra Wiechmann, OD. Click image to enlarge.

If you live in the South, you might be inclined to call any carbonated soft drink a “Coke,” much to the dismay of the Coca-Cola Company, which works to fiercely defend its brand name. Or perhaps you’re in the habit of calling any tissue a “Kleenex,” regardless of manufacturer. But the opposite problem—the proliferation of multiple brand names for inherently similar products—is often even more vexing and can also thwart clarity of communication.

Here in the eyecare profession, there’s a similar situation brewing about a fast-growing form of refractive surgery, but thought leaders are offering a proposal to quash it.

In 2011, Carl Zeiss Meditec created the refractive procedure originally described as refractive lenticule extraction (ReLEx) and now commonly known as SMILE, or small-incision lenticule extraction; this name change was done to highlight its incorporation of a small incision as opposed to the flap-dependent lenticule removal process typical of other approaches. The term has stuck, establishing itself as the descriptor used by doctors for other new and similar lenticule-based approaches emerging from competitors in more recent years.

However, with the rise in popularity of refractive lenticule extraction procedures, a recent editorial points out that other companies are unable to use Zeiss’s proprietary term SMILE for their newer approaches, despite its colloquial use amongst doctors for these procedures generally.

Competitors have added their own terminology to describe their proprietary work, and three are currently on the market outside the US but likely to come here in time: corneal lenticule extraction for advanced refractive correction (CLEAR) by Ziemer, smooth incision lenticule keratomileusis (SILK) by Johnson & Johnson and small incision-guided human-cornea treatment, with no acronym but rather the brand name “SmartSight,” by Schwind. Contrast this with the universal adoption of “LASIK” to describe any laser-assisted, flap-based refractive procedure regardless of the technology platform used.

Although these new and nuanced lenticule extraction techniques are an exciting development in eye care, the editors of both Journal of Cataract & Refractive Surgery and Journal of Refractive Surgery warn that “a proliferation of new proprietary terms aimed at market differentiation can also create confusion and obscure the common mechanistic underpinnings of these procedures.”1 The two journals jointly published an editorial—written by prominent refractive surgeons William J. Dupps Jr, Bradley Randleman, Thomas Kohnen, Sathish Srinivasan and Liliana Werner—offering a potential way forward.

These esteemed surgeons decided to come up with a generic term that may be used for all procedures spanning the class. They emphasize that, “as the editors of scientific journals dedicated to the field of refractive surgery, we recognize a responsibility to agree upon a common term for these procedures that can be used as a nonproprietary descriptor alongside any other necessary methodological details that make it clear which tools and settings were used to perform the procedure under study.”1 Doing so, they urge, is crucial for discovering closely related research publications as category entries rise with differing procedure names.

The team's deliberation on an all-inclusive term focused on the goals of descriptive accuracy, sufficient specificity differentiating the procedure type form others, sufficient breadth to include all possible variations within the same procedure class and avoidance of any proprietary names. The editors settled on keratorefractive lenticule extraction, or KLEx—pronounced “kay-lex”—citing its inclusion of references to the tissue altered (cornea), purpose of alteration (refractive) and mechanism of alteration (lenticule extraction). The term is not dissimilar to Zeiss’s original label refractive lenticule extraction, offering a grounding in the procedure’s origins but now stripped of branding.

The journal editors’ efforts are admirable, but once a profession has organically adopted a new term into its lexicon, it’s difficult—but not unheard of—to manufacture a change. Contact lens specialists worked to drop the off-putting term rigid from rigid gas permeable lenses to make the product more palatable to consumers; they are now commonly called gas permeable or GP lenses.

Are these advocates swimming against the tide or will surgeons, optometrists and patients be able to pivot to KLEx? Time will tell. Send us your thoughts on the matter at

Table 1. Current Keratorefractive Lenticule Extraction Procedures2-5


Name of Procedure

Shortened Proprietary Name

Claimed by Manufacturer

Carl Zeiss Meditec

Small-incision lenticule extraction


· Minimally invasive with incision less than 4mm

· Outer corneal layer does not need to be removed

· Corneal nerves stimulating tear glands less affected

· Corneal stability maintained through unaffected upper corneal layers


Corneal lenticule extraction for advanced refractive correction


· Low energy concept provides maximal precision, minimal tissue damage, minimal side effects and less inflammatory response as well as fast visual recovery

Johnson & Johnson

Smooth incision lenticule keratomileusis


· Anterior and posterior surface matching with no corneal folding when lenticule removed from cornea

· Better preserved biomechanical strength of cornea and faster nerve regeneration from less corneal fibers cut


Small incision-guided human-cornea treatment


· Intelligent eye tracking and cyclotorsion compensation

· Improved comfort due to curved patient interface

· Greater precision through accurate centering even with high astigmatism

· Tissue-saving through optimized lenticular geometry


1. Dupps Jr. WJ, Randleman B, Kohnen T, Srinivasan S, Werner L. Scientific nomenclature for keratorefractive lenticule extraction (KLEx) procedures: a joint editorial statement. J Cataract Refract Surg. 2023;49(11):1085.

2. SMILE: a brief guide to minimally invasive laser eye surgery. Carl Zeiss Vision International GmbH. Published January 9, 2020. Accessed October 26, 2023.

3. CLEAR. Ziemer Ophthalmic Systems AG. Accessed October 26, 2023.

4. Johnson & Johnson Vision receives CE mark approval for new corneal refractive technology, the ELITA femtosecond laser system. Johnson & Johnson Vision. Published March 1, 2023. Accessed October 26, 2023.

5. SmartSight: the minimally invasive lenticule extraction. SCHWINDeye-tech solutions. Accessed October 26, 2023.