Several medical conditions, eye measurements, and life circumstances can disqualify you from LASIK, either permanently or temporarily. Some are absolute dealbreakers, while others only delay the procedure until the underlying issue is resolved. A thorough pre-surgical screening will evaluate all of these factors, but knowing them in advance can save you time and money before you even book a consultation.
Keratoconus and Corneal Problems
Keratoconus is the most well-known disqualifier. In this condition, the cornea progressively thins and bulges into a cone shape, causing severe astigmatism and distorted vision. LASIK works by reshaping corneal tissue, and performing it on a cornea that’s already structurally compromised can accelerate the bulging and make vision dramatically worse. Keratoconus is considered an absolute contraindication, meaning no amount of careful planning makes it safe.
Even without a full keratoconus diagnosis, corneal mapping during your screening can reveal early or subtle thinning patterns that raise red flags. Your surgeon will also measure your corneal thickness to ensure there’s enough tissue to work with. LASIK involves cutting a flap and then removing tissue underneath, so the remaining corneal bed needs to stay above roughly 275 microns to maintain structural integrity. If your corneas are too thin to begin with, there simply isn’t enough material to safely reshape.
Unstable Prescription
Your eye prescription needs to have been relatively stable for at least one year before LASIK. If your vision is still shifting, the correction the laser makes today could be wrong six months from now, leaving you right back in glasses. This is one of the main reasons LASIK isn’t performed on teenagers. Most surgeons require patients to be at least 18, and many prefer to wait until the mid-20s, when prescriptions are more likely to have leveled off.
Autoimmune and Immune Conditions
Autoimmune diseases like lupus and rheumatoid arthritis can interfere with how your body heals after surgery. The corneal flap created during LASIK needs to heal cleanly, and an immune system that attacks its own tissues makes complications more likely. The American Academy of Ophthalmology lists uncontrolled autoimmune disease as an absolute contraindication.
That said, “uncontrolled” is the key word. If you have an autoimmune condition that’s been in remission or well-managed on a single medication for at least six months, with no history of eye complications and normal tear function, some surgeons will consider you a candidate. People with moderate to severe disease or those requiring multiple medications to stay stable are generally excluded. A rheumatologist’s clearance confirming disease inactivity is typically part of the process.
HIV and other immunodeficiency conditions fall into the same category, as they compromise the body’s ability to fight infection and heal tissue at the surgical site.
Diabetes
Diabetes is listed by the FDA as a relative contraindication, meaning it doesn’t automatically disqualify you but raises significant concerns. Uncontrolled diabetes is an absolute disqualifier because high blood sugar impairs wound healing and can cause unpredictable changes in vision. Diabetic eye disease, even in early stages, also rules out the procedure.
If your diabetes is tightly controlled, with an A1C below 7.5 for at least six months and no signs of complications in your eyes or elsewhere, some surgeons will proceed. But you’ll face more scrutiny during screening, and any evidence of diabetic changes in the retina will stop the process.
Severe Dry Eye
LASIK temporarily worsens dry eye because the procedure cuts corneal nerves that help regulate tear production. For most people, this resolves within a few months. But if you already have significant dry eye before surgery, the post-operative dryness can become chronic and genuinely debilitating.
During screening, tear production is measured using a small strip of paper placed at the edge of the lower eyelid. Wetting of 5 millimeters or less in five minutes indicates poor tear flow and raises concern. Severe, pre-existing dry eye syndrome is a disqualifier, though mild cases can sometimes be treated beforehand to bring you into the eligible range.
Large Pupils
When your pupils dilate beyond the zone the laser treats, light entering through the untreated outer cornea can scatter and cause glare, halos, and starbursts, particularly at night. This becomes a practical concern when pupils exceed about 7 millimeters in dim lighting, because the laser’s treatment zone often can’t be made large enough to match. Younger patients and people taking certain medications tend to have larger pupils.
Modern wavefront-guided lasers have reduced this risk compared to earlier technology, and large pupils are no longer the automatic disqualifier they once were. But if your pupils are very large and your corneas are on the thinner side (limiting how wide the treatment zone can go), the combination may still take you out of the running.
Medications That Affect Healing
Certain medications can disqualify you from LASIK or require you to stop them well in advance. The FDA specifically flags retinoic acid (used in acne treatments like isotretinoin) and steroids as medications that may prevent proper healing. Isotretinoin is particularly notable because it causes significant dryness of the eyes and skin, and most surgeons want patients off it for six months to a year before considering surgery.
Medications that cause vision fluctuations are also a concern, since they make it impossible to get an accurate baseline prescription for the laser to correct.
Pregnancy and Breastfeeding
Hormonal changes during pregnancy and breastfeeding can temporarily shift your prescription and alter the shape of your cornea. The hormone prolactin, which drives milk production, may directly affect corneal tissue. Because of this, LASIK is not recommended until three conditions are met: you’ve completely stopped breastfeeding, your regular menstrual cycle has returned, and your eye prescription has returned to its pre-pregnancy values. For many women, this means waiting several months after weaning before getting screened.
Other Eye Conditions
Glaucoma can disqualify you because the suction applied to your eye during LASIK temporarily raises eye pressure, which is dangerous when pressure is already elevated. Advanced cataracts are also a disqualifier, since the lens clouding affects vision independently of the corneal issue LASIK corrects. Active eye infections or injuries need to be fully healed before any procedure. And a history of herpes simplex or herpes zoster affecting the eye raises the risk of reactivation triggered by the surgery.
Temporary vs. Permanent Disqualifiers
It’s worth distinguishing between factors that permanently rule out LASIK and those that just delay it. Keratoconus, severe autoimmune disease, and uncontrolled diabetes are often permanent barriers. An unstable prescription, pregnancy, breastfeeding, medication use, and treatable dry eye are temporary. Once the underlying issue resolves, you can be re-evaluated.
If you’re disqualified from LASIK specifically, that doesn’t necessarily mean all vision correction surgery is off the table. Procedures like PRK (which doesn’t create a corneal flap and preserves more tissue) or implantable lenses may be options for people whose corneas are too thin or whose eyes aren’t suited for LASIK. Your screening evaluation will typically include a discussion of alternatives if LASIK itself isn’t safe for you.