How Is Candidacy for Refractive Surgery Determined?
Dr. Guillermo Enríquez TostadoNovember 7, 20269 min read
In this article
Summary: Knowing whether you are a candidate for refractive surgery depends on more than your prescription or your answers to an online questionnaire. The assessment should consider the stability of your vision, the health of your cornea and ocular surface, your medical history, medications, activities, and expectations. A questionnaire can help guide an initial conversation, but it does not replace a complete eye exam or allow you to determine for yourself that you are approved for surgery.
Candidacy is determined through a comprehensive evaluation
Refractive surgery includes procedures that reshape the cornea or use an implant to reduce dependence on eyeglasses or contact lenses. LASIK is one of the best-known options, but alternatives such as PRK, SMILE, or phakic intraocular lenses are also available. The choice should not be based only on popularity or another person's outcome.
According to the Preferred Practice Pattern of the American Academy of Ophthalmology, the initial evaluation should include a medical and eye history, visual acuity with and without correction, refraction measurement, corneal topography or tomography, corneal thickness, and an assessment of the tear film and ocular surface. A dilated eye exam may also be needed to check other structures of the eye. The National Eye Institute notes that a LASIK evaluation requires a comprehensive dilated eye exam.
That’s why candidacy cannot be summed up by a “yes” or “no” answer obtained online. The result depends on a combination of findings and the procedure being considered.
What clinical factors are reviewed?
The first part of the assessment aims to determine whether your eyes are in suitable condition for a procedure and whether the measurements are reliable.
- •Prescription stability: if your eyeglass or contact lens prescription has changed recently, it may be necessary to postpone the decision. The FDA identifies refractive instability as a factor that may make surgery less appropriate.
- •Corneal shape and thickness: topography and tomography help identify irregularities, thinning, or conditions such as keratoconus. Measuring just one point on the cornea is not enough: its shape and the amount of tissue that would remain after treatment are also evaluated.
- •Ocular surface: dry eye, blepharitis, eye allergies, or problems with the eyelid glands can affect the accuracy of measurements and increase discomfort afterward. The American Academy of Ophthalmology review on preoperative evaluation for LASIK emphasizes the need to identify and treat these problems before surgery.
- •General health and medications: some autoimmune diseases, wound-healing problems, uncontrolled diabetes, pregnancy or breastfeeding, and certain medications can affect visual stability or recovery. These factors should be reviewed on an individual basis.
- •Other eye problems: glaucoma, eye inflammation, herpes around the eye, cataracts, previous surgeries, or injuries can change the balance between risks and benefits.
- •Pupils and night vision: pupil size in low-light conditions and the visual quality required for your job or daily activities may be relevant. The FDA warns that some people may experience glare, halos, ghost images, or difficulty driving at night.
Having one of these factors does not always mean that no surgery is possible. In some cases, it may be necessary to treat an ocular surface condition first, wait for the prescription to stabilize, choose another technique, or determine that the risks outweigh the benefits.
The ocular surface and cornea can change the plan
Dry eye deserves a specific evaluation because it can cause fluctuating vision and make a measurement appear different from one moment to the next. In addition, refractive surgery can cause or worsen dryness symptoms. The American Academy of Ophthalmology describes preoperative evaluation of the ocular surface as an important part of reducing this risk.
During the consultation, the tear film, tear breakup time, surface staining, eyelids, and meibomian glands may be evaluated. If an abnormality is present, the specialist may recommend treating it and repeating the measurements before making a decision. Surgery on an unstable ocular surface can affect both planning and visual quality afterward.
The cornea is also studied using maps that show its curvature and elevation. This helps identify patterns that may be consistent with diseases that could increase the risk of corneal weakening. However, the results should not be interpreted in isolation or used as a do-it-yourself rule to approve yourself for surgery.
Expectations and lifestyle are also part of candidacy
Being a candidate does not necessarily mean surgery is the best decision for you. What you hope to achieve and what risks you are willing to accept also matter.
Surgery may reduce the need for eyeglasses or contact lenses for some activities, but it does not guarantee complete freedom from them. The National Eye Institute explains that LASIK does not correct presbyopia, the age-related change that makes it harder to focus up close. As a result, many people may need reading glasses at some point, even if they have had good distance vision after surgery.
Possible incomplete results, the need to continue using vision correction, the possibility of an additional procedure, and symptoms such as dryness, blurred vision, light sensitivity, halos, or glare should also be discussed. The FDA recommends weighing risks and benefits according to personal priorities, without basing the decision solely on testimonials, promotions, or price.
- •Stable prescription — Why it matters: It helps ensure planning is based on a representative measurement. · What it does not establish on its own: It does not confirm that the cornea is suitable.
- •Normal topography or tomography — Why it matters: It makes it possible to study the shape and characteristics of the cornea. · What it does not establish on its own: It does not replace the medical history or evaluation of the ocular surface.
- •No dry eye symptoms — Why it matters: It reduces the chance of overlooking an ocular surface problem. · What it does not establish on its own: It does not rule out eye disease without an examination.
- •Desire to stop wearing eyeglasses — Why it matters: Helps clarify the person’s goal. · What it does not establish on its own: It does not show that the benefits outweigh the risks.
Why isn’t an online questionnaire enough?
A questionnaire may ask about age, eyeglass prescription, contact lens use, medical conditions, or symptoms. This information may help organize a consultation, but it has important limitations: it depends on the respondent’s interpretation, does not measure the cornea, does not examine the optic nerve or retina, and cannot confirm tear film stability.
In addition, two people with a similar eyeglass prescription may have different risks because of differences in the cornea, ocular surface, pupil, medical history, or visual demands at work. Even the most suitable procedure may not be the same for both.
The consultation should also allow you to compare alternatives: continuing to wear glasses or contact lenses, considering another refractive technique, or not having surgery. A second opinion may be reasonable if there are questions about the recommendation, the tests, the proposed technique, the risks, the interpretation of the tomography, or expectations for the outcome.
Frequently asked questions
Does having a low eyeglass prescription mean I’m a candidate?
Not necessarily. Your prescription is just one piece of information. The cornea, ocular surface, prescription stability, general health, and expectations also play a role.
If a form says I’m a candidate, can I schedule surgery now?
No. A form can serve as an initial guide, but the decision requires an eye exam, diagnostic tests, and an informed conversation about alternatives, benefits, limitations, and risks.
Is a second opinion necessary for everyone?
There is no single rule. It may be especially helpful if the recommendation is unclear, you have received different opinions, you have a relevant eye history, or you do not understand how the technique was chosen.
Conclusion: candidacy is confirmed during a consultation
If you’re wondering, “Am I a candidate for refractive surgery?”, the answer should not be based solely on your age, eyeglass prescription, or a digital questionnaire. Candidacy is determined through a comprehensive evaluation that combines tests of the cornea and ocular surface, a review of your medical history, visual stability, everyday needs, and realistic expectations.
An ophthalmologic assessment should also explain what alternatives are available and under what circumstances it may be more prudent not to have surgery. If you’re considering refractive surgery, you can request a consultation to review your case individually via WhatsAppat the office.
References
- •National Eye Institute: Surgery for Refractive Errors. Update listed on the page: 5 of November 2025.
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This content is for informational purposes only and does not replace a medical consultation or constitute a diagnosis.
This information is for guidance only and does not replace a medical consultation, diagnosis, or treatment. Each case is assessed in person.
