SMILE: procedure guide
Lenticule extraction: a lenticule is shaped inside the cornea and removed through a small incision, so there is no flap.
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Quick answer
SMILE corrects short sightedness with or without astigmatism by shaping a lenticule inside the cornea with a femtosecond laser and removing it through a small incision. There is no flap, and the incision is what the procedure is named for.
General educational information about a subject, not an assessment of your own eyes. Suitability and treatment decisions are made by a qualified ophthalmologist who has examined you.
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- Procedure
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SMILE
SMILE stands for small incision lenticule extraction. A femtosecond laser cuts a thin lens-shaped piece of tissue inside the cornea, and the surgeon removes it through an incision measured in millimetres. Removing that lenticule changes the shape of the cornea, which is what corrects the focus.
Because nothing is lifted away from the surface of the eye, the questions readers ask about SMILE tend to be about that difference rather than about the laser: what the incision means for the surface of the eye, for dryness, and for contact sport in the first weeks.
How it differs from a flap procedure
LASIK lifts a flap to reach the tissue it reshapes. SMILE leaves the surface layer intact and reaches the same tissue through a small cut, which is the source of most of the reported differences between them: how the surface of the eye behaves afterwards, and how the procedure feels during the first hours.
The comparison is not a ranking. Each approach places different demands on the cornea, and the measurements taken at an assessment decide which demands a particular eye can meet.
What it can correct
SMILE is used for short sightedness, with or without astigmatism. That combination is the one the procedure was designed around, and the amount that can be corrected depends on corneal thickness and regularity.
Long sightedness is treated differently, and presbyopia is a change in the lens rather than in the cornea, so neither is corrected by reshaping the cornea alone.
Recovery, side effects and safety
Vision usually becomes functional quickly, while refraction keeps settling for weeks and dryness is commonly reported in the early months. Your surgeon decides when driving, sport, swimming and eye makeup resume, and those instructions override any general guidance.
Reported risks are much the same set as for other refractive procedures, including under- and over-correction, glare and halos at night, dryness, and rare complications. The likelihood for one person is an individual question, and it is discussed at an assessment rather than answered in general.
Also known as small incision lenticule extraction, lenticule extraction
Questions about SMILE
Each answer below is the short version; the question links to the page that carries it in full, with sources.
- Does SMILE leave a flap?
No. SMILE creates no flap. A lenticule is shaped inside the cornea and removed through a small incision, so the surface of the eye is not lifted as it is in LASIK.
- What is the difference between PRK and SMILE?
PRK removes the outer corneal layer and reshapes the surface, while SMILE removes a shaped piece of tissue from inside the cornea through a small incision. Both avoid a flap, and they differ mainly in recovery speed and in how the eye surface is left.
- What is the main difference between SMILE and LASIK?
The difference is the access route. LASIK lifts a flap and reshapes beneath it; SMILE shapes a lenticule inside the cornea and removes it through a small incision. The rest of the treatment plan is built the same way, from your measurements.
- Who cannot have SMILE?
SMILE is generally not used where the prescription falls outside the range the technique can address, where the cornea is unstable or irregular, or where the ocular surface is too dry to measure and heal reliably.
- Can SMILE treat high short sightedness?
SMILE is used at higher short sighted prescriptions than some older surface techniques, but what can be treated still depends on the cornea rather than on the prescription alone.
- Can SMILE be done on one eye only?
Treating a single eye is possible and is sometimes deliberate, for instance where the two eyes have very different prescriptions or where only one eye is suitable. Much more often both eyes are treated, either on the same day or a short time apart.
- What is the difference between SMILE and Femto LASIK?
Both use a femtosecond laser, but Femto LASIK uses it to create a flap that is then lifted, while SMILE uses it to create an incision and a lenticule. The excimer reshaping step that follows is where the rest of the difference lies.
- How does laser eye surgery work in general?
All laser vision correction procedures remove or reshape corneal tissue to change the eye’s focusing power, and they differ mainly in how the laser reaches the tissue it needs to reshape.
- How does SMILE compare with an implantable lens (ICL)?
SMILE reshapes the cornea and removes tissue; an implantable lens leaves the cornea intact and adds a lens inside the eye. They are used in different situations, most often at high prescriptions where too much corneal tissue would be needed.
- Should I ask how many procedures my surgeon has performed?
Yes, and it is a reasonable question to ask directly. Surgical experience is one of the few things about a clinic that a patient can actually check, alongside licensing and what the quoted price covers.
- LASIK or SMILE: how does a surgeon actually choose?
The choice is made from your measurements rather than from your preference or from a general claim about which is better. Corneal thickness, corneal shape, prescription, tear film and the planned correction all feed into it.
- Which procedure has the fastest recovery?
Flap and lenticule procedures generally settle more quickly than surface treatments, because the outer layer of the cornea is left intact. Beyond that the differences between individual procedures are smaller than the differences between individual patients.
All 104 SMILE questions, searchable
Where this is covered in full
- How SMILE works
Lenticule extraction explained: what the laser cuts, and what it removes.
- What is SMILE Pro?
What the procedure is, how lenticule extraction works, what it corrects and who it may suit.
Related subjects
- Myopia (short sightedness)
The eye focuses light in front of the retina, so near objects are clear and distant ones are blurred. It is the refractive error most commonly treated with laser vision correction.
- Astigmatism
The cornea is curved unevenly, so light is focused differently across different axes and the blur is not the same in every direction. It commonly occurs alongside short or long sightedness.
- Blurred vision
Vision that is soft or unclear. It has many causes, from an uncorrected prescription to a change inside the eye, and only an examination can say which one applies.
- SMILE Pro
The current generation of the SMILE platform, built around a faster laser and an automated centring step. The clinical idea is unchanged: a lenticule is removed through a small incision.
- LASIK
Flap-based laser vision correction: a thin surface layer of the cornea is lifted, the tissue beneath it is reshaped, and the layer is replaced without stitches.
- PRK
Surface treatment: the outer layer of the cornea is removed and the tissue beneath it is reshaped, with no flap and no lenticule. The surface then regrows, which is why the first week is slower.
- SMILE vs PRK
Both leave the surface of the eye intact in different ways: one through a small incision, one by removing the surface layer and letting it regrow. The first week is the main difference.
- Dubai
The emirate where most of the UAE refractive surgery capacity is, and the one most international patients travel to. Licensing, clinic choice and what a quote should contain are the local questions.
- Femto LASIK
LASIK in which the flap is created by a femtosecond laser instead of a mechanical instrument, which is a difference in how the flap is made rather than in what the procedure corrects.
- ICL
An implantable lens is placed inside the eye in front of the natural lens. Nothing is removed from the cornea, which is why it comes up where a prescription is outside what corneal procedures can treat.
- LASIK vs SMILE
A flap procedure against a flapless one. The difference readers care about is what happens to the surface of the eye, not which laser is better.
- LASIK in Dubai
LASIK is performed at licensed eye facilities across Dubai, so availability is not the useful filter. What separates two quotes is the assessment behind the plan and who operates.
This page describes what is generally true about smile. It is not a diagnosis, and it cannot say whether a treatment is suitable for you, because suitability depends on measurements taken during an examination.
Sources & further reading
We prefer primary sources. Where a claim comes from a manufacturer, a single study or a regulator, it is labelled as such below.
- Laser In Situ Keratomileusis (LASIK) Clinical reference StatPearls, NCBI Bookshelf
The equivalent clinical reference chapter for LASIK, used so that comparisons describe both procedures symmetrically.
Used for How LASIK creates and manages a corneal flap; LASIK complication categories.
Link checked 22 September 2026
- American Academy of Ophthalmology Professional body American Academy of Ophthalmology
A large professional body publishing both clinical guidance and plain-language patient education on refractive surgery.
Used for Cross-checking patient-facing explanations of refractive surgery.
Link checked 22 September 2026
- Small Incision Lenticule Extraction (SMILE) Clinical reference StatPearls, NCBI Bookshelf
A continuously updated clinical reference chapter covering SMILE indications, technique, outcomes and complications, written for clinicians.
Used for How the lenticule is created and removed; Indications and contraindications; Complication categories; Corneal biomechanics compared with flap-based surgery.
Link checked 22 September 2026
- Comparison of clinical outcomes of LASIK, Trans-PRK, and SMILE Peer-reviewed literature Peer-reviewed literature (via PubMed Central)
A comparative study of three commonly used refractive procedures, including a summary of proposed advantages of each.
Used for The procedure comparison page, particularly the PRK discussion.
Link checked 22 September 2026
- Comparison of clinical outcomes following small incision lenticule extraction with the VISUMAX 800 and VISUMAX 500 Peer-reviewed literature Peer-reviewed literature (via PubMed Central) · 2025
A single comparative study of SMILE performed on the newer and older generations of the ZEISS platform. A single study, not a pooled analysis.
Used for The SMILE vs SMILE pro section, explicitly labelled as single-study evidence.
Link checked 22 September 2026
- European Society of Cataract and Refractive Surgeons Professional body ESCRS
A European professional society for refractive and cataract surgery, publishing guidance and outcome registries.
Used for Refractive surgery outcome measurement and reporting.
Link checked 22 September 2026
- Refractive surgery and dry eye: an update Peer-reviewed literature Peer-reviewed literature (via PubMed Central) · 2023
An update on how different refractive procedures affect the ocular surface, with attention to preoperative screening for dry eye.
Used for Why tear film assessment belongs in preoperative screening.
Link checked 22 September 2026
- Post-LASIK dry eye disease: A comprehensive review of the current literature Peer-reviewed literature Peer-reviewed literature (via PubMed Central)
A review of dry eye after LASIK, including the mechanisms involved and how other procedures compare in the published literature.
Used for Balanced comparison of dry-eye risk between procedures.
Link checked 22 September 2026
- Dry Eyes After SMILE Peer-reviewed literature Peer-reviewed literature (via PubMed Central)
A review of ocular surface changes after SMILE, including how dry-eye signs and symptoms are measured and how they change over the first postoperative months.
Used for Explaining why dry eye is a key preoperative consideration.
Link checked 22 September 2026
- The Royal College of Ophthalmologists Professional body The Royal College of Ophthalmologists (UK)
The UK professional body for ophthalmologists, which publishes standards and commissioning guidance for refractive surgery services.
Used for What good preoperative assessment and consent look like.
Link checked 22 September 2026
- Cochrane Library Peer-reviewed literature Cochrane
Systematic reviews and meta-analyses. Useful for readers who want to know how strong the pooled evidence is, not just what one trial found.
Used for Helping readers judge the strength of the evidence base.
Link checked 22 September 2026
- EyeSmart: eye health information for the public Patient information American Academy of Ophthalmology
Patient-facing material from the largest ophthalmology professional body, covering conditions, tests and treatments outside refractive surgery.
Used for Cross-checking patient-facing explanations of non-refractive eye conditions; Describing what tests such as dilation and OCT involve.
Link checked 23 September 2026
- Dry Eye after Small Incision Lenticule Extraction (SMILE) versus Femtosecond Laser-Assisted In Situ Keratomileusis: A Meta-Analysis Peer-reviewed literature Journal of Ophthalmology (via PubMed Central) · 2016
A meta-analysis pooling several studies on dry eye after SMILE compared with femtosecond LASIK. It also documents where the included studies disagreed.
Used for The dry-eye discussion on the comparison and risks pages; Explaining that the evidence base is mixed rather than unanimous.
Link checked 22 September 2026
- ZEISS VISUMAX 800 Manufacturer documentation ZEISS Medical Technology
The manufacturer’s own product page for the femtosecond laser platform used for SMILE pro.
Used for What describes the technology behind SMILE pro; The distinction between SMILE and SMILE pro; Claimed workflow features such as automated centration.
Link checked 22 September 2026
- SMILE Laser Eye Surgery: What to Expect Clinical reference Cleveland Clinic (YouTube)
Hospital patient education describing what happens before, during and after small incision lenticule extraction. It describes the typical course of treatment rather than predicting any individual outcome.
Used for What SMILE involves, for readers arriving before the procedure pages; What the period immediately after treatment is typically like.
Link checked 23 September 2026
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