Preparation
Contact lenses out at least three days beforehand. No make-up, and no need to fast. Anaesthetic eye drops, then a lid speculum is placed to hold the eyelids open.
Home / Refractive surgery / LASIK
LASIK
Laser-Assisted in Situ Keratomileusis, corneal flap
LASIK is the most widely performed refractive surgery technique, and the one with the longest clinical track record: more than twenty-five years. A femtosecond laser cuts a corneal flap, an excimer laser reshapes the deeper layer, and the flap is then laid back without stitches.
7 secondsFlap creation per eye
30 secondsPhotoablation per eye
~ 24 hoursFunctional vision
All refractive errorsMyopia, hyperopia, astigmatism
The procedure
How the operation is done.
As a day case, under anaesthetic eye drops, in the laser suite of the Institut Voltaire (Paris, 11th arrondissement). Consultation, assessment and follow-up take place at the practice in Rueil-Malmaison.
Femtosecond laser
The VisuMax 800 creates the flap in contact with the eye, in seven seconds. You feel pressure, not pain.
Excimer laser
The flap is lifted, then the Schwind Amaris reshapes the stroma in about thirty seconds. You look at a point of light; a tracking system stops the laser if the eye moves too much.
Repositioning
The flap is laid back and adheres on its own. No stitches. Treatment starts three to four hours later. The refraction settles over one to three months.
The five stages of LASIK: front view, then vertical cross-section of the cornea
Anaesthetic eye drops, then a lid speculum is placed. No injection and no general anaesthesia.
The femtosecond laser cone comes into contact with the cornea, held in place by a suction ring. Its beams outline a superficial flap, attached by a hinge.
The flap is lifted and folded back on its hinge, exposing the stroma to be treated.
The excimer laser reshapes the stroma to a depth of a few tens of microns, following the profile calculated before the operation.
The flap is put back in place and adheres on its own: no stitches.
Treated zone Epithelium Stroma, flap Laser beam Instrument
Strengths and limitations
What it does well, where it falls short.
No technique is better than the others in absolute terms. Each has situations where it is the best answer, and a downside you should know about before choosing.
| Strengths | Limitations |
|---|---|
| The fastest recovery: functional vision within 24 hours in most cases, quality of vision restored in about a week. | A flap is created: complications can occur when it is cut or handled. It can shift and need to be repositioned in the hours that follow. |
| Painless: the procedure and the first hours afterwards are comfortable, unlike PRK. | Dry eye: cutting corneal nerves disrupts the tear reflex. It is more common than after PRK or SMILE, and improves with time. |
| Predictable results: its nomograms are the best established, across all refractive errors. | Uses up corneal thickness: the flap takes up part of it, which limits high corrections. |
| Simple enhancement: the flap can be lifted again, which no other corneal technique allows. | Contact sports: the flap can still be dislodged by a hard blow, which is why I prefer Trans-PRK for people in exposed jobs or sports. |
| Little fluctuation in vision compared with Trans-PRK. | · |
LASIK fees
€3,000both eyes
€1,500per eye
All-inclusive fee: surgeon's fees, clinic and laser suite 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 fixed allowance. Full fee information
Side effects and complications
What to expect, and what is rare.
The expected side effects come with the technique: they are common and temporary. Complications are rare, and they are listed here because you have the right to know about them before you consent.
Expected side effects
- Dry eye: usual in the first few weeks, treated with artificial tears.
- Halos and glare at night: common, caused by light scatter and by the pupil dilating. They fade as the eye heals.
Possible complications
- Epithelial ingrowth: surface cells migrate under the flap and reduce the quality of vision. The interface has to be washed out.
- Under- or overcorrection: requires an enhancement.
- Corneal ectasia: a rare, progressive bulging of the cornea, made more likely by a cornea that is too thin or by undiagnosed keratoconus. This is what the assessment is designed to rule out.
- Infection: rare, prevented with an antibiotic.
Who it suits
Indications.
These criteria are a guide, not a verdict: only the pre-operative assessment measures the actual geometry of your eyes.
Good candidates
- Myopia, hyperopia and astigmatism, within the limits set by corneal thickness
- Sufficient corneal thickness, checked by pachymetry
- Regular topography, with no sign of keratoconus
- A healthy tear film, or dry eye treated beforehand
- Refraction stable for two years, aged 21 or over
What rules it out or means waiting
- Keratoconus, or a suspicion of it on topography
- A cornea too thin for the intended correction
- Severe dry eye
- Combat or contact sports, or a job with a risk of blows to the eye
- Pregnancy, breastfeeding, a refraction that is still changing
Enhancement
What if the result is not perfect?
Re-treatment after LASIK
The flap can be lifted again and the excimer laser completes the correction. It is the simplest re-treatment in refractive surgery, and often decisive for high corrections, where an enhancement is more likely.
Undercorrection or regression remains possible whatever the technique. Any enhancement is included in the first year of follow-up.
Other techniques
SMILE
No flap, and the biomechanics of the cornea are better preserved.
Trans-PRK
No deep cut, for thin corneas and eyes at risk of blows.
ICL phakic lens
When the cornea does not allow laser treatment.
SFO information leaflet (in French)
Published by the French Society of Ophthalmology (Société Française d'Ophtalmologie, SFO), it describes the operation, its results and its risks. It forms the basis of informed consent, but does not replace the consultation.
Frequently asked questions
What patients ask me most often.
Does LASIK hurt?
No. Anaesthesia is given with eye drops and the operation is painless. Discomfort and watering are common for two to three hours afterwards.
How long does LASIK take?
Seven seconds to cut the flap and about thirty seconds of excimer laser per eye. Allow around ten minutes in theatre for both eyes.
When can I go back to work?
The next day in most cases: that is when functional vision returns. Quality of vision (contrast, no halos) takes about another week. Non-contact sport after one week, swimming pools after two weeks. When you can drive again depends on the acuity measured at the check-up, not just on how much time has passed.
Can the flap move?
It is very rare, and happens mainly in the hours after the operation or after a direct blow. That is why you wear a protective shield at night and are told not to rub your eyes.
Can LASIK be repeated later?
Yes, by lifting the existing flap again, provided enough corneal thickness remains.
Is LASIK 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.
Dr Emmanuel Halimi
Ophthalmic surgeon · RPPS 10100555084 · Medical Council of Hauts-de-Seine no. 92/23003
Page written and approved by the surgeon.
Last medical review: