The core criteria
Age and stability: 18+ and a prescription stable for around 12 months. Teenagers and fluctuating powers are deferred.
Corneal shape: topography and tomography must show a regular, non-ectatic cornea. Early keratoconus (forme fruste) is a stop sign, not a speed bump.
Corneal thickness: enough tissue must remain after any reshaping, with a safety margin. Thickness decides whether laser is possible at all — and which kind.
Tear film: significant dry-eye disease is treated first; it skews measurements and worsens post-operative comfort.
Pupil and optics: large pupils in dim light raise the theoretical halo profile; wavefront data refines candidacy.
Eye health beyond the cornea: pressure, lens clarity and retina must be normal; retinal thinning in high myopia is assessed and secured before any elective procedure.
General health: uncontrolled autoimmune disease, pregnancy or breastfeeding, and certain medications prompt deferral or reconsideration.
Expectations: the wish for “perfect permanent vision” is gently recalibrated into the honest goal: substantially reduced dependence on glasses.
What a suitability consultation involves
Expect a thorough visit: refraction (often both manifest and cycloplegic), corneal tomography, thickness mapping, tear-film assessment, pupil measurement, eye-pressure check and dilated retina examination — typically 2–3 hours including dilation recovery. Contact-lens wearers must pause lens use beforehand (days for soft lenses, longer for rigid) so measurements read the true cornea. You leave with either a clear candidacy verdict with options, or a clear explanation of why now is not right — including what could change that answer.
Common reasons for a “not now” or “not this procedure”
Thin corneas redirect toward PRK or ICL. Suspicious topography redirects toward cross-linking discussions or simple monitoring. Active dry eye redirects toward ocular-surface treatment first. Unstable power means waiting. High hyperopia or presbyopic-age goals shift the conversation toward lens-based options rather than corneal laser. Each redirection protects the one thing no procedure can replace: the long-term health of your cornea and eye.