Candidacy guide

Am I a Candidate for LASIK? Self-Check Before Your Exam

You may be a LASIK candidate if you are 18 or older (many clinics prefer your 20s), your prescription has been stable for a year, your eyes are healthy and your corneas are thick and regular enough. Thin corneas, dry eye or keratoconus can rule LASIK out, but SMILE, PRK or ICL may still work.
Reviewed November 2026 · Seoul LASIK Clinic Directory
Am I a Candidate for LASIK? Self-Check Before Your Exam

What makes someone a good LASIK candidate?

A good candidate is an adult with a stable prescription, healthy eyes, adequate corneal thickness and normal corneal shape, plus realistic expectations.

The US FDA lists reasons you may not be a good candidate: a prescription that changed in the last year, thin corneas, dry eyes, unusually large pupils, autoimmune or other conditions that slow healing, medications such as steroids, and eye disease beyond needing glasses. Clinics in Korea apply similar criteria. See LASIK surgery in Korea.

LASIK self-check list

Answer honestly; one "no" does not rule you out, but it is worth raising at your exam.

Question Favours LASIK Talk to the surgeon
Are you 18 or older? Yes, ideally early 20s+ Under 18
Has your prescription been stable for 12+ months? Yes Changed in the last year
Are your eyes free of disease other than refractive error? Yes Keratoconus, glaucoma, cataract, past eye injury
Do you have dry or irritated eyes? No or mild Moderate to severe dry eye
Has anyone mentioned thin corneas? No Yes
Do you have an autoimmune disease or diabetes? No, or well controlled Yes, uncontrolled; see LASIK with diabetes
Are you pregnant or breastfeeding? No Yes; wait until hormones settle (see LASIK and pregnancy)
Do you play contact sports or have a combat job? No Yes; PRK or SMILE may suit better
Can you stop contact lenses before the exam? Yes No
Do you accept that results are not guaranteed? Yes Expecting perfect vision

How old do I need to be?

The minimum is 18 for FDA-approved lasers, but many surgeons prefer patients in their 20s, when prescriptions are more likely to be stable.

There is no strict upper age limit; after about 40, presbyopia and early cataract change the decision. Read LASIK age limits.

How do I know if my corneas are thick enough?

Only a measurement can tell you. Your exam maps thickness and shape across the cornea.

Average central thickness is about 540–550 µm. Surgeons calculate how much tissue your correction removes and how much remains, aiming for a residual stromal bed of at least 250 µm, often 300 µm, and a percent tissue altered below about 40%. Details in corneal thickness for LASIK.

Is my prescription too strong or too weak for LASIK?

Very strong prescriptions are often better treated another way, and very mild ones may not justify surgery.

The FDA notes that you may not be a good candidate if you need an unusually strong prescription, or if you only wear glasses or contacts some of the time, since the benefit may not outweigh the risks. Strong myopia removes more corneal tissue with any laser, which is why surgeons often suggest an implantable lens instead; the US EVO ICL label covers -3.0 to -20.0 D. Astigmatism is commonly treated alongside myopia. Your surgeon will explain where your numbers fall; compare options in ICL vs LASIK.

Can I get LASIK with dry eyes or astigmatism?

Astigmatism is usually treatable; dry eye needs treatment first and may steer you toward another procedure.

LASIK can make dry eye worse for months, so clinics test tear quality and may treat it before surgery. SMILE cuts fewer corneal nerves and ICL avoids the cornea. See astigmatism correction in Korea and dry eye after LASIK.

Which health conditions and medications matter?

Anything that affects healing or the surface of the eye matters, so tell the clinic about your full medical history.

The FDA highlights autoimmune disease, other major or chronic illness that might slow or alter healing, and medications such as steroids that may prevent healing. It also flags your job: some careers restrict or prohibit refractive surgery, so check with your employer or licensing body first if you are a pilot, in the military or in another regulated role. Unusually large pupils in dim light can increase night glare and halos, and the exam measures this. None of these automatically rules you out, but each needs a frank conversation with the surgeon.

What if I'm not a LASIK candidate?

Many people turned down for LASIK can still have vision correction.

If a clinic finds keratoconus, ask about corneal cross-linking, which aims to strengthen the cornea rather than correct your prescription. Compare the alternatives in LASIK vs PRK and ICL vs LASIK.

How should I prepare for the candidacy exam?

Good preparation makes your measurements more accurate and your consultation more useful.

  • Stop contact lenses in advance. Korean ophthalmologists commonly advise about one week for soft lenses, two weeks or more for hard lenses and three to four weeks for orthokeratology lenses; follow your clinic's instructions.
  • Bring your history. Old glasses prescriptions help show stability; bring your medication list and any eye surgery records.
  • Plan for dilation. Drops can blur near vision and cause glare for about 4–6 hours, so do not drive afterwards.
  • Allow time. The exam usually takes about 1.5–2 hours.
  • Think ahead to surgery day. The FDA notes you may need to go 24–36 hours without eye makeup before surgery.

What happens next?

Book a full pre-op exam and ask the ophthalmologist which procedures are safe for your eyes.

Read what happens at the pre-op eye exam in Korea and bring our questions to ask your LASIK surgeon. This page is general information, not a diagnosis.

Sources

Key facts

  • Age: at least 18 (FDA-approved lasers); many clinics prefer early to mid-20s
  • Stable prescription: no significant change in the past 12 months
  • Corneas: thick and regular enough to leave a safe residual stromal bed
  • Eye health: no keratoconus, uncontrolled glaucoma or severe dry eye
  • Exam: only a full pre-op exam can confirm; see pre-op eye exam in Korea

Independent directory. Prices are typical ranges reported by Seoul clinics and change often. Always confirm a written quote and get a full eye exam before booking. This page is general information, not medical advice.

FAQ

Frequently asked questions

What disqualifies you from LASIK?

Common reasons include an unstable prescription, thin or irregular corneas such as keratoconus, significant dry eye, uncontrolled autoimmune disease or diabetes, pregnancy and certain medications. Many of these people can still have PRK, SMILE or ICL.

Can I get LASIK with high myopia?

Sometimes, if your corneas are thick enough. For high prescriptions, surgeons often recommend ICL instead because it removes no corneal tissue.

Can I get LASIK if I have astigmatism?

Yes, most astigmatism can be treated with LASIK or SMILE. Very high or irregular astigmatism may need another approach, such as a toric ICL.

How long before the exam should I stop wearing contact lenses?

Korean clinics commonly advise about one week for soft lenses, two weeks or more for hard lenses and three to four weeks for orthokeratology lenses. Confirm with your clinic.

Is there an online test that confirms I'm a candidate?

No. Online quizzes can only screen for obvious issues. Candidacy needs corneal mapping, thickness measurement and an ophthalmologist's examination.

Planning vision correction in Seoul?

Compare clinics by district, check 2026 price ranges, and read our step-by-step planning guide for international patients.