Preparation
Contact lenses out at least three days before. Anaesthetic eye drops, then an eyelid speculum is put in place. There is no need to fast.
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SMILE
Small Incision Lenticule Extraction, without a flap
SMILE does not cut a flap. The femtosecond laser shapes a lenticule within the thickness of the cornea, which is then removed through an incision a few millimetres long. The structure of the cornea is better preserved and fewer surface nerves are cut, so dry eye after the operation is often less marked.
14 secondsTo cut the lenticule, per eye
No flapAn incision a few millimetres long
24 to 72 hFunctional vision
Since 2024Hyperopia up to 7 dioptres
The procedure
How the operation is done.
As a day case, under anaesthetic eye drops, on the laser platform at the Institut Voltaire (Paris 11th). Consultation, assessment and follow-up take place at the practice in Rueil-Malmaison.
Femtosecond laser
The VisuMax 800 shapes the lenticule in contact with the eye, in fourteen seconds. A peripheral micro-incision is made at the same time.
The surgical step
The lenticule is grasped and removed through the incision. It is painless. No second laser is needed: everything is done on the same machine.
Healing on its own
The incision closes by itself. The treatment starts three to four hours later. The refraction settles over one to three months.
The five stages of SMILE: front view, then a vertical cross-section of the cornea
Anaesthetic eye drops, then an eyelid speculum is put in place. No injection and no general anaesthesia.
A cone comes into contact with the cornea and holds it still with gentle suction while the cut is made.
Within the thickness of the cornea, the femtosecond laser outlines a lens of tissue and a peripheral micro-incision. No flap is cut.
A fine spatula, inserted through the micro-incision, separates the lenticule from the surrounding tissue, first above it, then below.
The lenticule is grasped and removed in one piece through the micro-incision, which closes on its own, without stitches.
Treated area Lenticule removed Stroma Laser beam Instrument
Strengths and limits
What it does well, and its limits.
No technique is better than the others in absolute terms. Each has situations where it is the best answer, and a downside you need to know about before choosing.
| Strengths | Limits |
|---|---|
| Greater safety: no flap, so no complications from cutting, handling or displacing one. | Recovery a little slower than LASIK in the first week: functional vision within 24 to 72 hours, with contrast and quality of vision still lagging behind at seven days. The gap usually closes within a month. |
| Corneal biomechanics better preserved than with LASIK, since the front layers stay intact. | Shorter clinical track record for hyperopia: only since 2024, against twenty-five years for LASIK. Early results are comparable, but long-term data are still lacking. |
| Less dry eye: fewer of the surface corneal nerves are cut. | Enhancement is trickier: there is no flap to lift again. It requires surface PRK or the CIRCLE technique. |
| A single laser: no change of machine during the operation. | Cost: the equipment used is more expensive. |
| Hyperopia treatable since 2024: the CE-marked SMILE pro module corrects up to seven dioptres. It is only available on the VisuMax 800, and the laser platform where I operate has one. | Limited availability: the hyperopia module only exists on the VisuMax 800. Few laser platforms in the Paris region (Île-de-France) have one; the one where I operate does. |
SMILE fees
€3,300both eyes
€1,650per eye
All-inclusive fee: surgeon's fees, clinic and laser platform costs, consumables and post-operative follow-up. Not covered by French national health insurance (Assurance Maladie); many top-up health insurance policies (mutuelles) include a set allowance. Full fee information
Side effects and complications
What to expect, and what is rare.
The expected side effects come from the technique itself: they are common and temporary. Complications are rare. They are listed here because you have the right to know about them before you give your consent.
Expected side effects
- Dry eye: present, but usually less than after LASIK.
- Halos and glare at night: these fade as the eye heals.
Possible complications
- Incomplete removal of the lenticule: rare; it makes the procedure longer and may mean a second operation.
- Loss of suction during the cut: rare; it interrupts the procedure, which can then be resumed.
- Epithelial ingrowth into the interface: the interface has to be washed out.
- Under- or over-correction, corneal ectasia and infection: as with any corneal surgery.
Who it suits
Indications.
These criteria point the way; they do not decide. Only the pre-operative assessment measures the actual geometry of your eyes.
A good profile
- Myopia (short-sightedness) and myopic astigmatism, the original indication and the best documented
- Hyperopia (long-sightedness) up to seven dioptres since 2024, on the VisuMax 800
- Patients who want to avoid a flap: sport, occupation, personal preference
- Moderate dry eye, where SMILE is preferable to LASIK
- A cornea of sufficient thickness with a regular topography
What rules it out or means waiting
- Keratoconus, or a topography that suggests it
- A cornea too thin for the intended correction
- High corrections beyond the limits of lenticule extraction
- Cases where an enhancement is likely and LASIK would be the more cautious choice
- Pregnancy, breastfeeding, a prescription that is still changing
Enhancement
What if the result is not perfect?
A second treatment after SMILE
SMILE leaves no flap to lift. There are two options: surface PRK, or the CIRCLE technique. CIRCLE uses the femtosecond laser to cut a circular incision and a hinge around the original cap, turning it into a LASIK flap. The flap is lifted, the excimer laser corrects what remains, and the flap is laid back. Recovery is faster than after PRK, but the procedure demands great precision to avoid overlapping incisions and epithelial complications.
Under-correction or regression remains possible whatever the technique. Any enhancement is included in the first year of follow-up.
Other techniques
LASIK
The longest clinical track record; enhancement is simple.
Trans-PRK
No deep cut, for thin corneas.
ICL phakic lens
When the cornea does not allow laser treatment.
SFO information leaflet (in French)
This leaflet is published by the Société Française d'Ophtalmologie (French Society of Ophthalmology). It describes the procedure, its results and its risks. It serves as the basis for informed consent and does not replace the consultation.
Frequently asked questions
What I am asked most often.
What is the difference between SMILE and LASIK?
LASIK cuts a flap that is then lifted; SMILE removes a lenticule through a micro-incision, with no flap. Corneal biomechanics are better preserved and dry eye is less marked, but enhancement is trickier.
Does SMILE correct hyperopia?
Yes, since 2024, with the CE-marked SMILE pro module, up to seven dioptres. It is only available on the VisuMax 800 laser, which the platform where I operate has. LASIK still has a much longer clinical track record.
Does SMILE hurt?
No. Anaesthetic eye drops, and the procedure itself is painless. The days that follow are usually only mildly uncomfortable, because the surface of the cornea is not removed.
How is an enhancement done after SMILE?
With surface PRK, or with the CIRCLE technique, which turns the original cap into a LASIK flap so that the excimer laser can be applied.
Is SMILE safer than LASIK?
It avoids flap-related complications, which is a real advantage. But LASIK has a twenty-five-year track record and a simpler enhancement. Neither is better in absolute terms.
Is SMILE right for your eyes?
The questionnaire gives you a first indication in three minutes. The pre-operative assessment measures what cannot be guessed: topography, corneal thickness, tear film and a dilated eye examination (fundus examination).
Dr Emmanuel Halimi
Ophthalmic surgeon · RPPS 10100555084 · Medical Council of Hauts-de-Seine no. 92/23003
Page written and approved by the surgeon.
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