Am I a Good Candidate for LASIK? 12 Eligibility Criteria Explained

The 12 Core Eligibility Criteria

You're likely a good LASIK candidate if you meet ALL of these:

1. Age 18 or older (most surgeons prefer 21+)
2. Stable prescription for at least 12 months (no change >0.5 D)
3. Myopia between -1.0 and -10.0 D (some centres treat up to -12)
4. Hyperopia up to +5.0 D
5. Astigmatism up to -5.0 D
6. Adequate corneal thickness (typically 480 microns minimum)
7. No active eye infection or inflammation
8. No advanced dry eye disease
9. Healthy retina (no significant tears, holes, detachment risk)
10. No keratoconus or other corneal weakening conditions
11. No uncontrolled diabetes that affects healing
12. Not pregnant or breastfeeding (hormonal changes affect prescription)

Who Should NOT Have LASIK

LASIK is contraindicated if you have:

• Keratoconus or suspected keratoconus (cornea progressively thins and bulges)
• Severe dry eye that doesn't respond to treatment
• Autoimmune conditions like uncontrolled rheumatoid arthritis or lupus that delay healing
• Glaucoma — depends on type and control
• Cataract developing in the same eye
• Recent eye trauma or unstable cornea
• Pregnancy or breastfeeding (defer until 3 months after stopping)
• Under 18 — eyes still developing

A proper screening detects all of these before any surgery decision.

Age and LASIK: What Indian Patients Should Know

Under 18: Not eligible — eyes still changing.

18-21: Possible if prescription has been stable for 12+ months and refractive error is moderate. Most surgeons prefer to wait until 21.

21-40: Ideal LASIK age — stable prescription, good healing, longest benefit period.

40-50: Eligible, but you should understand presbyopia (near-vision loss) will develop on its normal schedule. Monovision LASIK can address this.

Over 50: Eligible if eyes are otherwise healthy and there's no early cataract. If cataract is forming, an IOL (intraocular lens) implant during cataract surgery may be a better long-term solution.

What If You're Borderline?

Many patients are 'borderline' — for example, your cornea is just thin enough, or your dry eye needs treatment first. Options include:

• Surface ablation (PRK or ASA): Removes corneal surface instead of creating a flap, requires less corneal thickness
• ReLEx SMILE: Preserves more corneal strength, sometimes works when traditional LASIK doesn't
• ICL (Implantable Collamer Lens): A soft lens placed inside the eye — an option for high prescriptions or thin corneas
• Treat dry eye first: 2-3 months of medical management can make some borderline patients eligible

The Pre-LASIK Evaluation: What to Expect

A proper LASIK candidacy assessment takes 60-90 minutes and includes:

• Detailed medical and eye history
• Refraction (with and without dilation)
• Corneal topography (Pentacam or similar)
• Pachymetry (corneal thickness measurement)
• Wavefront analysis
• Tear film and dry eye assessment (Schirmer test, TBUT)
• Pupil size measurement (for night vision planning)
• Detailed retinal examination

If any centre offers LASIK after only a 10-minute check, that's a major red flag.

Do I Qualify for LASIK? Who Qualifies and How the Decision Is Made

You qualify for LASIK if your prescription is stable, your power is within the range your cornea can safely treat, and your eyes are otherwise healthy — and only a full evaluation can confirm all three. The checklist above tells you whether you are likely to qualify; the scans decide it.

In practice, the surgeon weighs several measurements together rather than ticking each box separately:

• Your power and your corneal thickness together: A -3 D prescription and a -8 D prescription need very different amounts of tissue removed. The same cornea can be fine for one and too thin for the other.
• Corneal shape: Topography scans look for early or hidden keratoconus. An irregular pattern can rule out LASIK even if thickness is normal.
• Pupil size and night vision: Large pupils may need a wider treatment zone, which uses more tissue.
• Tear film: Dry eye that is not controlled usually has to be treated first.
• Your expectations and work: Someone who needs perfect night vision for driving or flying may be steered towards a different procedure or advised more cautiously.

If you do not qualify for LASIK, you may still qualify for SMILE, PRK/surface ablation or ICL. A good centre tells you which one — not just 'no'.

What Eye Power Is Suitable for LASIK? Minus, Plus and Cylinder

LASIK is usually suitable for minus power up to about -10.0 D, plus power up to about +5.0 D and cylinder (astigmatism) up to about -5.0 D, provided your cornea is thick and healthy enough. Some centres treat a little beyond these figures in selected eyes, and many surgeons are more cautious near the top of the range.

The ranges are only a starting point. What actually decides whether your prescription is suitable:

• Is it stable? No change of more than 0.5 D over at least 12 months.
• How much tissue would be removed? Higher power means deeper treatment. The surgeon calculates how much untouched cornea would remain after surgery and will not go below a safe margin.
• Is the power combined? High minus plus high cylinder in the same eye uses more tissue than either alone.
• Is it very low? Very small powers (for example -0.5 D) can be treated, but your surgeon will ask whether the benefit justifies surgery.

Can eyes be too bad for LASIK? Yes — but 'too bad' usually means too high a power for your cornea, or a cornea that is thin or irregular, not that your eyes cannot be corrected at all. For powers beyond laser limits, ICL (a lens placed inside the eye) can correct much higher minus power without removing corneal tissue. After about 45–50, refractive lens exchange is another option.

Can LASIK Treat Plus Power (Hyperopia)?

Yes, LASIK can correct plus power (hyperopia, or long-sightedness), usually up to about +5.0 D. Instead of flattening the centre of the cornea as it does for minus power, the laser steepens it by removing tissue in a ring around the centre.

A few things are different with hyperopic LASIK:

• Higher plus powers are less predictable than equivalent minus powers, and the effect can regress slightly over time. Many surgeons are conservative above about +4 D.
• Vision may take longer to settle — often several weeks to a few months.
• Plus power and age often overlap with presbyopia. Long-sighted people tend to need reading glasses earlier, so after 40 the plan often includes monovision or a lens-based option.
• For higher plus power, refractive lens exchange or a hyperopic ICL may be more suitable, depending on your age and eye anatomy.

If your plus power is mild and stable and you are under 40, hyperopic LASIK usually works well.

Can LASIK Be Done With a Thin Cornea?

LASIK can sometimes be done with a slightly thin cornea if your prescription is low, but a cornea that is thin for your power — or thin and irregular in shape — usually rules out flap-based LASIK. What matters is not one thickness number but how much healthy tissue will remain after treatment.

Your surgeon looks at:

• Thickness across the whole cornea, not just the centre, using pachymetry and tomography scans
• Whether the thinning is natural or a sign of keratoconus, which is far more important than the number itself
• How much tissue your power requires — a thin cornea with low power may be fine; the same cornea with high power may not

If your cornea is too thin for LASIK, the alternatives listed earlier — surface ablation (PRK/ASA), SMILE or ICL — are often still possible. If topography shows keratoconus, laser surgery is usually avoided altogether and corneal cross-linking may be advised to stabilise the cornea.

Contact Lens Wearers and the Best Time to Get LASIK

Yes, you can get LASIK if you wear contact lenses — most LASIK patients are long-term lens users. You simply need to stop wearing them for a period before your evaluation, because lenses temporarily reshape the cornea and can make measurements inaccurate.

Typical guidance (your clinic will give you exact instructions):

• Soft lenses: Usually stop for about 1–2 weeks before the evaluation.
• Toric (astigmatism) soft lenses: Often a little longer, around 2–3 weeks.
• Rigid gas-permeable (RGP) or hard lenses: Usually several weeks or more, and sometimes repeat scans are needed until the cornea is stable.

Wear glasses during this break. If your scans still change between visits, the surgeon will wait until they settle.

When should you get LASIK? The best time is once your prescription has been stable for at least a year, any dry eye is under control, and you can take a few quiet days for recovery. Practically, avoid scheduling it just before exams, a wedding, travel or a recruitment medical. If you are planning a pregnancy, it is usually better to have LASIK before or several months after pregnancy and breastfeeding. There is no medical advantage in waiting years once you are eligible.