Am I a Candidate for Laser Eye Surgery?
You are a candidate for laser refractive surgery if you clear age, prescription, cornea, dry eye, and topography gates. About 15 to 20 percent of consultations end with no laser procedure recommended. Below are the quantitative thresholds, the FDA and AAO sources behind them, and the Matcher to apply them to your eyes.
Seven conditions, in order of how often they disqualify.
- Age. LASIK and PRK: FDA floor 18; clinical practice prefers 21+. SMILE: FDA floor 22. EVO ICL: 21 to 45. RLE: typically 45+. Below the floor, the eye is still changing.
- Prescription stability. Refraction stable within ±0.5 D for at least 12 months (NBK549896). Bring two prior prescriptions to your consult.
- Diopter range fits FDA approval. SMILE: −1 to −10 D myopia, up to −3 D astigmatism (FDA P150040). EVO ICL: −3 to −20 D myopia, up to −4 D astigmatism. LASIK and PRK device labels vary but generally cover up to about −10 D myopia, +5 D hyperopia, −6 D astigmatism.
- Corneal thickness and residual stromal bed. RSB after ablation greater than 250 µm; many surgeons prefer 300 µm. SMILE additionally requires CCT greater than 475 µm and percent tissue altered under 40 percent. PRK can work with thinner corneas.
- Corneal topography. No keratoconus or forme fruste keratoconus. Pentacam or comparable tomography screens for this. Asymmetric astigmatism, inferior steepening, or thinning patterns disqualify corneal laser.
- Dry eye. Active uncontrolled dry eye disqualifies all corneal lasers until treated. Severe dry eye disqualifies entirely. Moderate dry eye steers away from LASIK toward SMILE or PRK.
- General health and pregnancy. No active autoimmune flare (lupus, rheumatoid arthritis, uncontrolled). Not pregnant or breastfeeding. No active ocular infection or herpes simplex keratitis history.
Soft factors that influence procedure choice but do not absolutely disqualify: mesopic pupil size larger than 7 mm (older devices had small optical zones; modern devices are usually fine), endothelial cell density for ICL candidates, and anterior chamber depth for ICL.
Quantitative thresholds, summarized.
| LASIK | PRK | SMILE | EVO ICL | RLE | |
|---|---|---|---|---|---|
| Min age | 18 | 18 | 22 | 21 | ~45 |
| Max age | None | None | None | 45 | None |
| Myopia range | to −10 D | to −10 D | −1 to −10 D | −3 to −20 D | IOL-driven |
| Hyperopia range | to +5 D | to +5 D | Not FDA-approved | Hyperopic version available | IOL-driven |
| Astigmatism max | −6 D | −6 D | −3 D | −4 D | IOL-driven |
| Min CCT | ~500 µm | ~460 µm | >475 µm | N/A | N/A |
| Min RSB | 250 µm | 250 µm | >250 µm | N/A | N/A |
| Topography | Normal required | Normal required | Normal required | Flexible | N/A |
| ACD requirement | N/A | N/A | N/A | ≥ 3.0 mm | N/A |
RSB, residual stromal bed. CCT, central corneal thickness. ACD, anterior chamber depth. Sources: NBK549896 (SMILE), FDA P150040 (SMILE), FDA EVO V4c approval, AAO Refractive Errors PPP 2025, PMC11110473 (ICL).
"LASIK is for everyone."
Approximately 15 to 20 percent of refractive-surgery consultations end with no laser procedure being recommended. The disqualifiers are mechanical (thin cornea, abnormal topography, prescription outside FDA range), physiological (uncontrolled dry eye, autoimmune flare, pregnancy), or temporal (unstable refraction). A clinic landing page rarely says this. The conversion math does not favor it. But the candidacy math is the candidacy math, and a surgeon doing a careful workup will tell some patients no. If your consult never includes the words "you are not a candidate for this procedure," ask why.
Before your consult.
- Your two most recent eyeglass or contact-lens prescriptions, ideally a year apart, to verify stability.
- A current eye exam within the last year if you have one. Topography or pachymetry numbers if your last optometrist did them.
- A list of dry-eye symptoms if you have any, with rough frequency and severity. The surgeon will probably administer an OSDI screen anyway.
- Your medication list, including hormonal contraception and any autoimmune therapies.
- Your honest answer to "what is your tolerance for glasses for reading after age 45?" This shapes whether monovision or RLE enters the conversation.
Stop wearing soft contact lenses for at least 3 to 5 days before the workup (longer for hard or gas-permeable lenses) so the cornea returns to its true shape.
Tell us about your eyes.
Frequently asked questions
What is the minimum corneal thickness for LASIK?
There is no single absolute floor because the figure that matters is the residual stromal bed (RSB) left after ablation. Most surgeons require RSB greater than 250 µm; many prefer 300 µm. A typical LASIK starting cornea (central corneal thickness, CCT) is therefore around 500 µm or more for routine corrections; deeper corrections need thicker corneas. For SMILE, FDA-approved labeling and StatPearls (NBK549896) cite CCT greater than 475 µm with RSB greater than 250 µm and percent tissue altered under 40 percent. PRK can work with thinner corneas because no flap is made.
Can I have laser eye surgery if I have keratoconus?
No. Keratoconus or any sign of forme fruste keratoconus on topography disqualifies LASIK, PRK, and SMILE. Removing corneal tissue from an already-weak cornea risks rapid progression and ectasia. The alternative pathway for keratoconus patients is cross-linking (CXL) to halt progression, sometimes followed by topography-guided surface ablation or a phakic IOL (EVO ICL) once the cornea is stable. A good refractive workup includes Pentacam or comparable topography and tomography specifically to screen for this.
Why is the minimum age for SMILE 22?
Two reasons. First, refractive error must be stable for at least 1 year before any laser correction. Eyes are still elongating into the early 20s in many patients. Second, the FDA approval letter for SMILE (P150040) specifies 22 years as the minimum, based on the trials that supported approval. LASIK and PRK have an FDA floor of 18, but the same stability rule applies in practice; many surgeons prefer to wait until 21 or older.
Does pregnancy disqualify me from LASIK?
Yes, during pregnancy and during breastfeeding. Hormonal changes cause transient shifts in refraction, corneal hydration, and tear production. Surgery during this window risks an inaccurate correction and unmasking of severe dry eye. Most surgeons defer all laser refractive surgery until at least 3 to 6 months after delivery and after breastfeeding stops, when the refraction is documented stable again.
What if my prescription is changing, can I still have surgery?
Not until it stabilizes. Standard requirement: refraction stable within ±0.5 D for at least 1 year (NBK549896). An unstable prescription means the correction the surgeon performs today will not match the eye in 12 months, and the patient ends up under-corrected or back in glasses. Bring at least two old prescriptions to your consult so the surgeon can verify stability.
Sources cited on this page
- StatPearls. Small Incision Lenticule Extraction (SMILE). NBK549896.
- US FDA. ZEISS VisuMax Patient Information Booklet. P150040C.
- US FDA. EVO Visian ICL (V4c) approval and labeling.
- American Academy of Ophthalmology. Refractive Errors and Refractive Surgery Preferred Practice Pattern (2025).
- Comprehensive review of LASIK, SMILE, and ICL outcomes including candidacy. PMC11110473.
Educational content only. Not medical advice. Final candidacy requires in-person ophthalmologist exam with topography, pachymetry, and biometry. We do not accept clinic sponsorship or referral commissions.
Failed a laser gate? The intraocular routes have their own gates and ledgers: the EVO ICL · RLE for presbyopia.