Age and stability
LASIK is approved for adults 18 and over. The more important number is stability: your prescription should have changed by no more than about half a diopter in the last year, because LASIK corrects the eye as it is today and a prescription that is still moving will move again afterward. Most patients are treated between their early twenties and mid forties. After about 45 the lens inside the eye stiffens and reading vision changes, and a lens based procedure often serves better than LASIK.
The range of prescriptions LASIK can treat
LASIK can correct nearsightedness up to roughly -10 to -12 diopters, farsightedness up to roughly +4 to +6, and astigmatism up to roughly 6 diopters, depending on corneal thickness and the surgeon's assessment. Higher prescriptions need more tissue removed, so a high prescription and a thin cornea together push the recommendation toward the EVO ICL, which corrects up to about -20 without removing any tissue.
Corneal thickness and shape
This is the factor patients cannot judge for themselves and the one that matters most. The cornea must be thick enough that, after the flap and the treatment, a safe amount of tissue remains. Its shape must be regular: corneal topography that shows steepening, asymmetry or thinning suggests keratoconus or a predisposition to it, and LASIK on such a cornea can cause it to bulge progressively. That is the complication called ectasia, and screening for it is the main purpose of the consultation imaging. A cornea that is too thin or slightly irregular may still be suitable for PRK or SMILE.
Dry eye
LASIK temporarily reduces corneal sensation, which reduces tear production for a few months. A patient with well controlled dry eye does fine; a patient with untreated dry eye may heal more slowly and see less crisply. The consultation assesses your tear film, and if it needs treatment first, that comes before surgery. For patients with significant dry eye the EVO ICL, which does not affect the corneal nerves, is often the better choice.
Health, medications and life circumstances
A few situations call for a different procedure or a delay:
- Pregnancy and breastfeeding, because hormones shift the prescription; wait until at least three months after
- Uncontrolled diabetes or autoimmune conditions that affect healing
- Medications that affect the corneal surface, such as isotretinoin
- Active eye disease, including infections, uveitis and untreated glaucoma
- A cataract, which should be treated with lens surgery that corrects the prescription at the same time
- Contact sports or occupations with a high risk of eye trauma, where a flapless procedure may be preferred
If you are not a LASIK candidate
Being told no for LASIK is not being told no for vision correction. PRK treats the surface and suits thinner or mildly irregular corneas. SMILE removes tissue through a small incision without a flap. The EVO ICL adds a lens inside the eye and suits high prescriptions and dry eyes. Refractive Lens Exchange replaces the natural lens and suits patients over 45. All are offered at our practice, and the consultation is designed to find the right one rather than to fit you to LASIK.
Is this right for your eyes?
Nothing on this page is a diagnosis. Whether this is the right choice for you is decided by a full examination at one of our 4 offices: Pasadena, Huntington Beach, Woodland Hills and Beverly Hills.
About this content: This page was written with the assistance of AI tools and reviewed for medical accuracy by Dr. Bavand Youssefzadeh, DO. It is general information, not medical advice, and does not replace an eye examination. Individual results vary. Read our medical disclaimer.
