Refractive surgery
Am I a candidate for laser eye surgery?
Your question
How do I know whether I can be operated on, and what might prevent it?
Our answer
Nobody can say without examining you. Eligibility is decided at the pre-operative assessment, which measures the prescription and its stability, the thickness and shape of the cornea, and the state of the ocular surface. That assessment exists as much to choose the technique as to turn down eyes that should not be operated on — early keratoconus first among them.
What the assessment measures
The pre-operative consultation is not paperwork: it is where the decision is made. It combines several examinations, some of which require contact lenses to have been left out for several days beforehand.
- The prescription, and its stability. A myopia still progressing is not ready; we operate on a stable error, checked against earlier prescriptions.
- Corneal thickness — pachymetry. It determines how much tissue can be removed without weakening the eye, and therefore which technique is possible.
- Corneal shape — topography. This is the key examination: it detects the irregularities that raise the suspicion of keratoconus, even early and entirely symptom-free.
- The ocular surface: significant pre-existing dryness worsens after laser surgery, and is treated beforehand.
- The retina, particularly in high myopia.
Keratoconus, the contraindication you cannot feel
This is why topography matters. Keratoconus is a progressive thinning and deformation of the cornea. Early on it may cause only an astigmatism that corrects well in glasses — nothing that would alert the patient.
Yet LASIK performed on such a cornea can accelerate it. Detecting a subclinical form is therefore a major contraindication, and precisely what a serious assessment sets out to exclude. In some borderline cases surface laser remains possible where LASIK is not; in others no refractive surgery is indicated at all, and that is the right answer.
Situations that postpone surgery
- Being too young, or a prescription still changing from year to year.
- Pregnancy and breastfeeding, during which refraction may vary.
- Untreated dry eye, or ongoing surface inflammation.
- Active eye infection, or a history of corneal herpes.
- A cornea too thin for the intended correction — which changes the technique, not necessarily the plan.
And when the lens begins to lose its clarity, or presbyopia is established, the question is no longer the cornea: lens surgery with implant placement answers the problem better.
What the assessment cannot promise
No refractive surgery guarantees permanent freedom from any correction in every circumstance. The aim is independence from glasses in daily life; presbyopia continues to progress with age and may bring back a need for reading correction. That belongs to the pre-operative discussion, not to the aftermath.
Further reading
Sources
- SFO — Information sheet 9A, corneal laser refractive surgery (January 2026)
- French health insurance — Myopia: treatment and follow-up
Updated 26 August 2026