LASIK (Laser-Assisted In Situ Keratomileusis) is a refractive surgery that corrects vision problems like nearsightedness, farsightedness, and astigmatism. The procedure uses a laser to precisely reshape the cornea, the clear, dome-shaped front surface of the eye. While LASIK has a high success rate, candidacy requires a comprehensive assessment of a patient’s age, vision stability, and overall ocular health.
The Standard Minimum Age for LASIK
The United States Food and Drug Administration (FDA) has cleared LASIK for individuals who are 18 years of age or older. This regulatory minimum is the earliest point a person may be considered, but it does not guarantee eligibility. Most providers advise patients to wait until their early to mid-twenties. This recommendation ensures that visual changes have fully subsided, as surgeons prioritize the maturity of the eyes over chronological age.
Why Visual Stability Is Non-Negotiable
The primary medical reason for the age restriction is the need for a stable vision prescription. Throughout adolescence and into early adulthood, the eye continues to grow, which often results in progressive changes to the refractive error, particularly nearsightedness (myopia). Performing a permanent correction on an eye that is still undergoing natural changes would mean the results of the surgery would be temporary and inaccurate in the long term.
Visual stability is defined as a prescription that has not changed significantly over a specific period. Surgeons require the prescription to have remained stable, meaning a change of less than 0.5 diopters, for at least 12 to 24 months prior to the procedure. This period of stability confirms that the eye has reached its mature refractive state. If LASIK is performed on an unstable eye, the refractive error may continue to progress, potentially requiring glasses, contacts, or a follow-up enhancement procedure later on.
Essential Health and Prescription Requirements
Beyond age and stability, several non-age-related factors determine suitability for LASIK. Corneal thickness is a primary concern because the laser removes tissue to reshape the cornea. Sufficient remaining tissue is necessary to maintain the eye’s structural integrity and prevent a rare complication called corneal ectasia. While the average corneal thickness is around 520 microns, surgeons often prefer a minimum of 500 microns, ensuring a residual stromal bed thickness of 250 to 270 microns remains after treatment.
Systemic health issues are also exclusionary factors, as certain conditions impair the healing process. Patients with uncontrolled diabetes are not candidates due to compromised healing and increased infection risk. Autoimmune disorders, such as rheumatoid arthritis or lupus, which affect the body’s ability to heal, may also disqualify a person from the procedure.
The severity of the refractive error itself limits candidacy, as LASIK is most effective within a specific range of prescription. LASIK is approved for nearsightedness up to -12.00 diopters, farsightedness up to +6.00 diopters, and astigmatism up to 6.00 diopters. Patients with prescriptions exceeding these levels often require the removal of too much corneal tissue, which would compromise the eye’s long-term health and stability. Severe dry eye syndrome or the presence of advanced eye diseases, such as glaucoma or cataracts, are further conditions that must be addressed before a patient can be considered eligible for LASIK.
Vision Correction Alternatives for Younger Patients
For younger individuals who do not meet the age or stability criteria, glasses and contact lenses are the safest standard methods of correction. These options provide temporary, non-surgical correction while the eye matures. Regular annual eye exams should be maintained to track prescription changes and monitor for the stabilization required for LASIK.
Patients ineligible due to thin corneas or high prescriptions have other surgical alternatives. Photorefractive Keratectomy (PRK) is a surface ablation technique suitable for those with thinner corneas because it does not require creating a corneal flap. Implantable Collamer Lenses (ICLs) are a reversible option where a lens is placed inside the eye, effective for very high prescriptions that exceed safe laser limits.