LASIK side effects and risks: what the evidence says
Is LASIK safe?
LASIK is an established procedure with a strong safety record, but it is surgery and has real risks. The AAO says about 90% of people end up with vision between 20/20 and 20/40 without glasses; serious complications are rare, while temporary side effects are common.
The FDA notes that results are generally worse for very large prescriptions, and that bilateral surgery on the same day carries more risk than one eye at a time. A full exam is the best protection: it screens out thin or irregular corneas, unstable prescriptions and eye disease.
What are the common side effects?
Common side effects are mostly temporary: dry eye, glare, halos, starbursts and fluctuating vision. In the FDA's PROWL studies (JAMA Ophthalmology, 2016), 43–46% of participants without visual symptoms before surgery reported at least one new one, such as glare, halos, starbursts or double images, at three months. Most were not bothersome, and only 1–4% were dissatisfied with their vision. See dry eye after LASIK.
How often do serious complications happen?
The table shows rates from AAO and peer-reviewed sources. Rates vary by study and technology.
| Complication | Reported rate | What it means |
|---|---|---|
| Early dry eye | 60–70% early on | Usually improves over 6–12 months |
| Intraoperative flap complications | 0.7%–6.6% historically | Lower with femtosecond lasers |
| Diffuse lamellar keratitis | 0.4%–4.38% | Inflammation under the flap; usually treated with drops |
| Flap displacement | About 0.012% over 12 months | Usually after trauma or rubbing; repositioned surgically |
| Infection | About 0.035% per procedure in a 204,586-eye study | Rare but potentially vision-threatening |
What other risks does the FDA list?
- Loss of vision: some patients lose lines of vision that glasses or further surgery cannot restore
- Under- or over-correction: may need an enhancement, which is not always possible
- Severe dry eye: occasionally permanent
- Night vision problems: reduced contrast in dim light or fog
- Monovision trade-offs: reduced depth perception
- Long-term effects: LASIK lasers were first approved in 1998
What is corneal ectasia?
Ectasia is a rare, serious complication in which the cornea weakens and bulges after surgery, blurring vision. Its main known risk factors are a thin or irregular cornea before surgery and early keratoconus. Pre-op corneal tomography is designed to detect this. Read corneal thickness for LASIK; if ectasia does develop, corneal cross-linking can help stabilise it.
Who should not have LASIK?
The AAO lists people who are usually poor candidates:
- Unstable or changing prescription, or under 18
- Extreme short- or long-sightedness or astigmatism
- Thin corneas, corneal scars, disease or keratoconus
- Severe dry eye, advanced glaucoma or a cataract affecting vision
- Poorly controlled diabetes or certain past eye infections
If you are not suited, ICL, PRK or SMILE may be. See am I a candidate for LASIK?
How can I lower my risk?
Choose a clinic that does a full exam, explains your results, and declines you if you are not suitable. Follow aftercare: use drops, wear the shield, do not rub. Bring questions to ask your surgeon. This is general information; no outcome is guaranteed.
How do LASIK risks compare with SMILE, PRK and ICL?
Each procedure trades one set of risks for another. None is risk-free, and the best choice depends on your eyes.
| Procedure | Distinctive risks | Notable advantage |
|---|---|---|
| LASIK | Flap complications; dry eye | Fast early recovery |
| SMILE | Slightly slower day-one sharpness; retreatment is more complex | No flap; generally less early dry eye |
| PRK / LASEK | Several days of pain; slower recovery; corneal haze | No flap; suits thinner corneas |
| ICL | Raised eye pressure, cataract, endothelial cell loss | No corneal tissue removed; lens can be removed |
For details see ICL recovery timeline, LASIK vs PRK and SMILE vs LASIK.
What happens if a complication occurs?
Most LASIK complications are treatable, especially when caught early. Inflammation under the flap (diffuse lamellar keratitis) is usually managed with more frequent steroid drops. A shifted flap is lifted and repositioned. Infection is treated with intensive antibiotic drops and close monitoring. Under- or over-correction may be improved with glasses, contact lenses or, once stable, an enhancement.
The FDA notes that some complications can cause lasting loss of vision, rarely. This is why it matters to know who will look after you if a problem appears after you fly home.
Before surgery, ask your clinic how it handles complications for international patients: whether follow-up messages or video calls are offered, whether retreatment within a set period is included in the price, and what records you will receive. Check whether your travel or health insurance covers problems arising from elective surgery abroad, as many policies exclude it. Keep your surgery summary, laser settings and prescriptions together so a local ophthalmologist can act quickly.
Does the choice of clinic change the risk?
Yes. The laser is only part of the outcome; screening and aftercare matter just as much. Look for a clinic that:
- Does corneal tomography, pachymetry, tear tests and a dilated exam before recommending a procedure
- Tells you clearly if you are not a good candidate
- Names the surgeon who will operate and lets you meet them
- Gives written aftercare, a 24-hour contact and records to take home
Browse LASIK clinics in Seoul and English-speaking vision clinics in Korea.
Sources
Key facts
- Vision outcome: about 90% reach 20/20–20/40 without glasses (AAO)
- New visual symptoms at 3 months: 43–46% (FDA PROWL)
- Dissatisfied with vision: 1–4% (FDA PROWL)
- Infection: about 0.035% of procedures
- Check suitability: Am I a candidate for LASIK?
Related guides
Independent directory. Prices are typical ranges reported by Seoul clinics and change often. Always confirm a written quote and get a full eye exam before booking. This page is general information, not medical advice.
FAQ
Frequently asked questions
What is the most common side effect of LASIK?
Dry eye. It affects most patients in the first weeks and usually improves over 6–12 months. Glare and halos around lights at night are the next most common.
Can LASIK make you blind?
Blindness from LASIK is extremely rare. The FDA notes that complications such as severe infection can, rarely, cause irreversible vision loss, which is why aftercare and early treatment of problems matter.
Do halos after LASIK go away?
For most people they fade over 3–6 months as the eye heals. A small number have lasting night vision symptoms, more often with large prescriptions or large pupils; your surgeon can assess this before surgery.
What happens if LASIK under-corrects?
Some people need an enhancement once vision is stable, usually after at least 3 months. The FDA notes further treatment is not always possible, for example if the cornea is too thin.
Is LASIK riskier in Korea than in the US or Europe?
The procedure and lasers are the same, so the risks are similar. What matters most is the clinic's screening, surgeon experience and aftercare, plus a plan for follow-up once you are home.
Planning vision correction in Seoul?
Compare clinics by district, check 2026 price ranges, and read our step-by-step planning guide for international patients.