LASIK (Laser-Assisted In Situ Keratomileusis) is a refractive surgery that reshapes the cornea to correct common vision problems. However, not everyone is.
Last reviewed: 2026-05-06
10 min read
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Content is educational and planning-oriented. It does not replace diagnosis, treatment, or personalized medical advice from a licensed healthcare professional. Outcomes vary by individual case.
This content is general education and does not replace evaluation by a licensed clinician. If you have symptoms, complications, or urgent concerns, seek in-person medical care.
Key takeaways
LASIK candidacy requires a comprehensive eye examination with specialized diagnostic equipment; self-assessment cannot determine eligibility.
Key criteria include age 18+, stable prescription for at least 12 months, adequate corneal thickness, and overall eye health.
Certain health conditions, medications, and life stages may temporarily or permanently affect candidacy.
Not qualifying for LASIK is a protective outcome, not a failure—alternative procedures may be recommended.
Is LASIK Right for You? Understanding Candidacy Basics
LASIK (Laser-Assisted In Situ Keratomileusis) is a refractive surgery that reshapes the cornea to correct common vision problems. However, not everyone is a suitable candidate for this procedure. Candidacy screening exists to protect patients and help ensure the best possible visual outcomes. For more background, see our eye health resources.
The purpose of this guide is to help you understand the clinical criteria that surgeons use when evaluating LASIK eligibility. This information may help you prepare meaningful questions for your consultation and feel more confident about the screening process.
What This Guide Covers
This resource covers the core eligibility criteria, health factors that affect candidacy, what to expect during your screening, and questions to discuss with your surgeon. It does not replace an in-person examination with a qualified refractive surgeon.
What Makes Someone a Good LASIK Candidate?
A good LASIK candidate generally meets specific criteria related to age, vision stability, ocular health, and overall physical health. These requirements are based on clinical guidelines from ophthalmology societies and regulatory standards for LASIK devices (AAO, ARSC).
The screening process helps identify patients who are likely to achieve satisfactory visual outcomes while minimizing the risk of complications. Being told you are not a candidate for LASIK is a protective outcome—it means your surgeon is prioritizing your eye health over proceeding with a procedure that may not be in your best interest.
Core Eligibility Criteria
Age Requirements and Vision Stability
The FDA requires LASIK candidates to be at least 18 years of age (FDA). This minimum age exists because younger patients' eyes may still be changing, and vision that is not yet stable can lead to suboptimal surgical outcomes.
Beyond the minimum age requirement, surgeons typically look for a stable prescription for at least 12 months before recommending LASIK (NVISION). Vision instability may indicate that myopia (nearsightedness), hyperopia (farsightedness), or astigmatism is still progressing. Operating on eyes with an unstable prescription may require enhancement surgery later.
Why Stability Matters
If your prescription has changed significantly within the past year, your surgeon may advise waiting until your vision stabilizes before proceeding with LASIK. This approach helps ensure more predictable and lasting results.
Some surgeons prefer to see patients in their mid-20s or later, when the eyes have fully matured and prescription changes are less likely. However, the 18-year minimum with documented stability is the standard clinical requirement.
Prescription Range Limits
LASIK can treat a range of refractive errors, but there are practical limits based on the amount of corneal tissue that can be safely reshaped. These limits are defined by FDA-approved treatment parameters (FDA, NVISION):
Myopia (nearsightedness): Typically treatable up to approximately -12.00 diopters
Hyperopia (farsightedness): Typically treatable up to approximately +6.00 diopters
Astigmatism: Typically treatable up to approximately 6.00 diopters
If your prescription exceeds these ranges, alternative procedures may be more appropriate. Your surgeon will discuss these options during your consultation if LASIK cannot safely address your prescription. Browse our eye treatments overview for a broader look at available procedures.
Corneal Health and Thickness
Corneal thickness is one of the most critical factors in LASIK candidacy. The procedure involves creating a thin flap in the cornea and reshaping the underlying tissue. Sufficient corneal thickness is necessary to create this flap safely while leaving adequate residual stromal bed to maintain corneal stability (AAO, ARSC).
Surgeons generally require a minimum corneal thickness of approximately 500 microns, with adequate residual stromal bed remaining after flap creation (NVISION). Patients with thin corneas may not have enough tissue for safe flap creation.
If your corneas are too thin for LASIK, your surgeon may recommend surface ablation procedures such as PRK (Photorefractive Keratectomy) or LASEK, which do not require creating a corneal flap. These alternatives may be appropriate for patients with thinner corneas or other corneal considerations (Cannon EyeCare).
Corneal Evaluation
Corneal thickness and shape are measured using specialized equipment during your screening. This information cannot be determined from a routine eye exam and requires dedicated diagnostic testing.
Health Factors That Affect Candidacy
Eye Conditions That May Disqualify
Certain eye conditions can affect LASIK candidacy or require treatment before surgery can be considered (AAO, NVISION):
Keratoconus and corneal irregularities: This progressive condition causes the cornea to thin and bulge into a cone shape. Patients with keratoconus or early corneal ectasia are generally not LASIK candidates because the procedure may weaken the cornea further.
Active eye infections or inflammation: Active infections such as herpes simplex keratitis or inflammatory conditions like uveitis must be fully resolved and stable before LASIK can be considered.
Severe dry eye syndrome: LASIK can temporarily reduce tear production, and patients with pre-existing severe dry eye may experience significant worsening of symptoms after surgery. Dry eye typically requires management before LASIK can be safely performed.
Cataracts: If cataracts are affecting your vision, cataract surgery with intraocular lens implantation may be a more appropriate solution than LASIK.
Systemic Health Considerations
General health conditions can impact healing and surgical outcomes (NVISION, Cannon EyeCare):
Autoimmune conditions: Disorders such as rheumatoid arthritis, lupus, or other autoimmune diseases may affect wound healing and increase the risk of complications. These conditions are often considered contraindications for LASIK.
Uncontrolled diabetes: Diabetes can affect corneal healing and may increase the risk of infection and other complications. Well-controlled diabetes may be acceptable, but this requires careful evaluation by your surgeon.
Immunodeficiency conditions: Impaired immune function can increase infection risk and affect healing responses.
Certain medications: Some medications, including high-dose corticosteroids and isotretinoin (Accutane), can affect corneal healing and may interfere with LASIK outcomes.
Always provide a complete medication list to your surgeon during screening.
Life Stage Factors
Pregnancy and breastfeeding: Hormonal changes during pregnancy and breastfeeding can cause temporary changes in vision and tear production. Most surgeons recommend waiting until several months after delivery and after breastfeeding has ended before undergoing LASIK (NVISION).
Hormonal fluctuations: Significant hormonal changes, whether related to pregnancy, medications, or other factors, can temporarily affect vision stability.
The LASIK Screening Process
Tests You Can Expect
A comprehensive LASIK candidacy evaluation typically takes 1–2 hours and involves multiple specialized tests (ARSC, Cannon EyeCare):
Corneal topography and tomography: Mapping the shape and curvature of your cornea to identify irregularities and measure thickness
Pachymetry: Measuring overall corneal thickness across different areas
Pupil size assessment: Evaluating pupil size in various lighting conditions, as large pupils may increase risk of night vision symptoms
Refraction testing: Confirming your current prescription through multiple testing methods
Tear film evaluation: Assessing tear production and quality, often using tests like Schirmer's test or tear break-up time
Dilated retinal examination: Examining the retina and optic nerve for any abnormalities
Wavefront analysis: Detecting higher-order aberrations that may affect visual quality
What to Expect
The screening process is comprehensive because each test provides different information that helps your surgeon determine whether LASIK is appropriate for your specific eyes. The evaluation may feel lengthy, but this thoroughness is designed to protect your vision.
What to Bring and How to Prepare
For your LASIK screening appointment:
Bring a list of current medications and any relevant medical records
Stop wearing contact lenses for a period before your appointment (your surgeon will specify the duration, as contacts can temporarily alter corneal shape)
Arrange transportation, as your eyes may be dilated and vision may be temporarily blurred after testing
Bring questions you want to ask your surgeon
When LASIK May Not Be Recommended
Understanding that LASIK may not be right for you is an important part of the screening process. Not qualifying for LASIK is not a failure—it indicates that your surgeon is prioritizing your safety and long-term eye health.
Some conditions that affect candidacy are temporary and may be addressed before reconsideration:
Uncontrolled dry eye can often be treated successfully
Active eye infections resolve with appropriate medication
Pregnancy and breastfeeding are temporary states
Some medications can be discontinued or substituted under medical supervision
Other conditions may be permanent contraindications, in which case your surgeon will discuss alternative procedures that may better address your vision needs.
Alternative Vision Correction Options
If LASIK is not suitable for your eyes, several alternative procedures may achieve similar visual outcomes (NVISION, Cannon EyeCare):
PRK (Photorefractive Keratectomy): This surface ablation procedure reshapes the cornea without creating a flap. It may be appropriate for patients with thin corneas or those at higher risk of flap complications. Recovery is typically longer than LASIK.
SMILE (Small Incision Lenticule Extraction): A minimally invasive procedure that removes a small piece of corneal tissue through a tiny incision. It may benefit patients with certain prescriptions and dry eye concerns.
Implantable Collamer Lens (ICL): A lens implanted inside the eye that corrects vision without reshaping the cornea. This option may be suitable for high prescriptions that exceed LASIK limits.
Your surgeon will recommend the most appropriate option based on your specific measurements, prescription, and eye health.
Questions for Your Consultation
Prepare to ask your surgeon the following during your screening. Meeting our ophthalmology team beforehand can also help you feel more informed:
What are my corneal thickness measurements and residual stromal bed after flap?
What is my pupil size in low-light conditions, and how does it affect my risk profile?
Do I have any early signs of corneal irregularities or conditions that concern you?
What treatment zone size do you recommend for my prescription?
What are realistic expectations based on my specific measurements?
If I'm not a LASIK candidate, what alternative procedures do you recommend?
What is your enhancement rate and policy if my vision changes after surgery?
Planning Your Next Steps
If you are considering LASIK as an international patient traveling to Istanbul, the screening process is an essential first step that cannot be skipped:
Verify your surgeon's credentials and hospital accreditation before committing — review our facility standards for guidance
Ask about the specific diagnostic equipment used during your evaluation
Understand the follow-up schedule and what happens if complications arise after you return home
Clarify the clinic's policy for revisions or enhancements if needed
Some clinics offer remote preliminary assessments for international patients, which may help identify obvious contraindications before you travel. However, a comprehensive in-person evaluation with specialized equipment is still required before surgery.
Your surgeon is your partner in protecting your vision. If you are told LASIK is not right for you, this decision is based on clinical factors designed to ensure the best possible outcome for your specific eyes.
