LASIK Risks and Side Effects: What the Research Actually Shows
How safe is LASIK overall
LASIK is one of the most extensively studied elective surgical procedures performed today. Large-scale studies consistently report patient satisfaction rates above 95 percent, and serious vision-threatening complications are rare in properly screened candidates. That said, no surgical procedure carries zero risk, and the FDA, the American Academy of Ophthalmology, and individual surgeons are clear that LASIK is not right for everyone. Understanding what the research actually shows helps you make an informed decision rather than relying on marketing claims in either direction.
Common, usually temporary side effects
- Dry eye: The most frequently reported side effect, affecting an estimated 20 to 40 percent of patients in the first months after surgery. Usually resolves within three to six months. Managed with artificial tears and prescription drops. More likely in patients with pre-existing dry eye.
- Night-vision disturbances: Halos, starbursts, and glare around lights affect many patients in the early months, especially in low light. Most improve significantly over six to twelve months as the cornea heals.
- Fluctuating vision: Vision can vary slightly during the healing period, especially in the first four weeks. This is normal and typically resolves as the corneal surface stabilizes.
- Light sensitivity: Common in the first few days and typically mild after the first week.
Less common but real risks
| Complication | Estimated rate | Notes |
|---|---|---|
| Undercorrection or overcorrection | 5 to 10 percent | May be resolved with an enhancement procedure |
| Regression over time | 5 to 10 percent over 10 years | More common with higher prescriptions |
| Persistent dry eye beyond 6 months | 1 to 3 percent | Higher risk with pre-existing dry eye |
| Flap complications | Less than 1 percent | Usually treatable if caught early |
| Ectasia (corneal thinning) | Less than 0.2 percent | Proper candidacy screening reduces risk sharply |
Use our LASIK cost and procedure comparison tool to weigh the financial and clinical trade-offs of different options based on your profile.
Who is at higher risk
Candidacy screening exists precisely to identify patients who face elevated risk. Thin corneas, large pupils, very high prescriptions, and pre-existing dry eye all increase the likelihood of side effects or complications. Keratoconus, even in a mild or subclinical form detectable only on topography, is a contraindication because LASIK can accelerate corneal thinning. Choosing an experienced surgeon who uses detailed corneal mapping and turns away borderline candidates is the most effective risk reduction available to patients.
What the FDA says
The FDA approved LASIK in 1999 and has conducted post-market studies since. A 2018 patient-reported outcomes study found that the majority of patients reported no quality-of-life problems after surgery, and satisfaction rates were high across the study population. The FDA also maintains a list of questions for patients to discuss with their surgeon before consent, covering the full range of potential side effects. Reviewing that list before your consultation is a practical way to ensure nothing important goes unasked.
How to reduce your personal risk
- Choose an experienced surgeon who has performed thousands of procedures on the specific laser platform they will use for you.
- Get a thorough pre-op evaluation including corneal topography, pachymetry, and tear-film testing, not just a brief screening appointment.
- Disclose all medications and health conditions including autoimmune disease, diabetes, and any history of dry eye.
- Follow post-op instructions precisely, especially avoiding eye rubbing and not skipping follow-up visits.
Frequently asked questions
Can LASIK cause permanent vision loss? Total loss of vision from LASIK is extremely rare. Some patients do not achieve perfect 20/20 results and may retain a residual prescription, but best-corrected vision is almost never worse after properly performed LASIK than before.
What is LASIK ectasia and how is it prevented? Ectasia is a progressive thinning of the cornea that can occur if too much tissue is removed or if the patient had undetected pre-existing corneal weakness. Proper candidacy screening with modern topography significantly reduces this risk.
Is LASIK safer now than it was 10 or 15 years ago? Yes. Laser technology, eye tracking, and pre-operative diagnostic tools have all improved substantially. Complication rates in more recent studies are lower than those documented in earlier generations of the procedure.
Bottom line
LASIK has a strong safety record in properly screened candidates, with serious complications being rare and patient satisfaction consistently high. The most common side effects, dry eye and temporary night-vision changes, are real but usually temporary. The most effective protection is a thorough candidacy evaluation with an experienced, licensed ophthalmologist who will turn away candidates who are not suitable rather than perform surgery on everyone who inquires. Ask your surgeon about their complication rates, their screening process, and exactly which risks apply to your specific anatomy.
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