Short answer
Most modern LASIK and SMILE Pro platforms correct myopia up to approximately −10 dioptres (D), often combined with up to roughly 5 D of astigmatism. The real limit is not always the laser range — it is whether your cornea has enough thickness for safe tissue removal at your prescription.
LASIK and SMILE Pro prescription limits
LASIK: typically up to −10 D sphere + astigmatism correction in one session. SMILE Pro: similar myopia range — flapless, often preferred for dry eye or contact sports, not higher limits.
Manufacturers and clinics quote maximum treatable ranges, but your surgeon applies stricter individual limits based on corneal thickness (pachymetry), optical zone size, and tomography (Pentacam). A −9 D prescription on a thick cornea may be straightforward; −7 D on a thin cornea may be declined for laser.
| Procedure | Typical myopia limit | Astigmatism | Main constraint |
|---|---|---|---|
| LASIK | Up to ~−10 D | Up to ~5 D cylinder | Corneal thickness after flap + ablation |
| SMILE Pro | Up to ~−10 D | Myopic astigmatism within range | Same — tissue removed, no flap |
| PRK / surface laser | Up to ~−8 to −10 D | Often combined | Longer recovery; same thickness rules |
| ICL | Up to ~−20 D | Toric ICL available | Anterior chamber depth — not corneal thickness |
Why corneal thickness matters more than the number
Laser surgery removes microscopic layers of corneal stroma. The surgeon must leave enough residual bed for structural safety — typically at least 250–280 µm depending on technique and platform.
Pre-operative mapping calculates exactly how much tissue your prescription requires. If the maths does not leave a safe residual bed, laser is not appropriate — even if your −Sph is within the brochure maximum. That is when ICL becomes the correct pathway: no corneal tissue removed.
Read: Can LASIK fix severe myopia? for high and severe prescriptions specifically.
How much can LASIK correct at your prescription?
- 1−1 to −3 D (mild): almost always within LASIK/SMILE range if otherwise healthy.
- 2−3 to −6 D (moderate): routinely corrected; corneal assessment confirms safety.
- 3−6 to −10 D (high): often possible with adequate thickness — ICL compared if borderline.
- 4Above −10 D (severe): laser usually not recommended; ICL up to −20 D.
See the full prescription table on the myopia guide.
Myopia plus astigmatism — same session?
Yes. LASIK, SMILE Pro, and toric ICL treat sphere (myopia) and cylinder (astigmatism) together — one procedure, one recovery.
Combined prescriptions do not reduce how much myopia can be corrected — they require a more precise treatment plan. Example: −5.50 / −2.00 × 180 = −5.50 D myopia + −2.00 D astigmatism, both corrected simultaneously.
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Next steps
- 1Compare LASIK in Turkey vs ICL in Turkey if you are near the −8 to −10 D range.
- 2Read LASIK vs ICL for the clinical trade-offs.
- 3Return to the myopia pillar guide for symptoms, causes, and full treatment overview.