Am I a Good Candidate for LASIK? Requirements and Eligibility

LASIK Candidacy: The Core Requirements

The majority of adults with common refractive errors are good LASIK candidates, but the procedure is not right for everyone. Candidacy is determined by a combination of factors — your age, the stability and magnitude of your prescription, the anatomy of your cornea, your tear film health, and the presence or absence of certain medical conditions. Only a comprehensive pre-operative evaluation can definitively confirm your candidacy.

Factor	Requirement	Why It Matters
Age	18+ (21+ preferred)	Prescription must be fully stable
Prescription stability	No change >0.50 D in 12 months	Changing Rx leads to regression
Myopia range	Up to -12.00 D	Higher Rx removes more tissue
Hyperopia range	Up to +6.00 D	Less predictable at higher levels
Astigmatism	Up to 6.00 D	Treated simultaneously
Corneal thickness	500+ microns minimum	Residual bed must stay >250 microns
Pupil size	Ideally <7 mm in dark	Large pupils increase halo risk
Eye health	No active disease	Several conditions disqualify

Age Requirements for LASIK

The FDA has approved LASIK for patients aged 18 and older, but most experienced surgeons prefer to wait until age 21, when the visual system has typically matured and prescriptions have stabilized. The key issue is not chronological age itself but prescription stability — the refraction should not have changed by more than 0.50 diopters in at least 12 months before surgery. For details, see our complete guide to LASIK age requirements.

There is also an upper age consideration. Patients in their mid-40s and beyond develop presbyopia — age-related loss of near focusing ability — which LASIK standard correction does not address. Options for older patients include monovision LASIK, which intentionally undercorrects one eye for reading, or reading about LASIK after 40 in detail.

Prescription Requirements

LASIK can treat a wide range of refractive errors, but there are practical upper limits determined by how much corneal tissue can be safely removed. The FDA-approved ranges for LASIK are: myopia up to -12.00 diopters, hyperopia up to +6.00 diopters, and astigmatism up to 6.00 diopters. In practice, most surgeons achieve their best and most predictable results at the lower end of these ranges — myopia up to -8.00 D and hyperopia up to +4.00 D. For detailed information, see LASIK prescription limits.

Patients with very high myopia (above -10.00 D) or hyperopia may be better served by Implantable Collamer Lens (ICL) surgery, which does not require corneal tissue removal and can treat higher prescriptions with excellent outcomes.

Corneal Requirements: Thickness and Shape

Corneal anatomy is the most critical determinant of LASIK candidacy. Two measurements are essential: thickness (pachymetry) and shape (topography). Corneal thickness must be adequate to allow the planned tissue removal while leaving a residual stromal bed of at least 250 microns — this safety buffer prevents corneal weakening and ectasia. Most patients have corneas around 530 to 560 microns thick; the surgery removes 10 to 15 microns per diopter of correction. See our complete page on corneal thickness requirements.

Corneal topography screens for keratoconus — a progressive thinning condition that can be worsened catastrophically by LASIK. Early or subclinical keratoconus disqualifies a patient from LASIK entirely, as removing tissue from an already-weakened cornea risks severe vision loss. Advanced topography screening can detect patterns suspicious for keratoconus long before the condition is clinically apparent.

Conditions That Disqualify You from LASIK

Several conditions are absolute contraindications — meaning they rule out LASIK regardless of other factors. Others are relative contraindications that require careful evaluation. See the full list in our LASIK disqualifying conditions guide.

• Keratoconus — progressive corneal thinning; LASIK is absolutely contraindicated
• Severe dry eye syndrome — LASIK worsens existing dry eye; see LASIK with dry eyes
• Autoimmune diseases — lupus, rheumatoid arthritis, Sjögren's syndrome impair healing
• Glaucoma or uncontrolled eye pressure — the suction ring used during flap creation raises IOP
• Active eye infections or inflammation — surgery must be deferred until resolved
• Pregnancy and breastfeeding — hormonal changes alter corneal shape and refraction; see LASIK during pregnancy
• Uncontrolled diabetes — impairs wound healing and corneal sensitivity
• Cataracts — if cataracts significantly affect vision, cataract surgery should be performed first

Borderline Candidates: When the Answer Isn't Clear

Some patients fall into a gray zone where candidacy depends on which technology is used, how conservative the treatment plan is, or whether an alternative procedure is more appropriate. Borderline-thick corneas, mild dry eye, and higher prescriptions all require individualized assessment. A surgeon experienced with multiple procedure options — LASIK, PRK, SMILE, and ICL — is better positioned to match the right procedure to borderline cases than one who performs only LASIK.

If You Are Not a LASIK Candidate

Not qualifying for LASIK does not mean you cannot have laser or surgical vision correction. PRK achieves the same visual outcomes as LASIK without creating a corneal flap, making it the preferred alternative for thin corneas and certain professionals who cannot risk flap complications. SMILE uses a small incision rather than a flap and is associated with less dry eye risk. ICL adds a lens inside the eye without removing corneal tissue, treating prescriptions up to -20 diopters. Explore all options in our vision correction procedures guide or schedule a consultation to find out what is right for your eyes.