LASIK Risks and Complications: What the Data Actually Shows

Putting LASIK Risks in Context

LASIK is one of the most extensively studied elective surgical procedures in medical history, with more than 25 years of peer-reviewed data from tens of millions of procedures worldwide. Major complication rates have declined substantially as technology and screening protocols have improved. When performed by an experienced surgeon using current technology with thorough pre-operative screening, LASIK is among the safest surgical procedures available.

That said, informed consent requires understanding what can go wrong — even rarely. This guide presents the most current data on side effects and complications, distinguishing between those that are common and temporary versus those that are rare and potentially permanent.

Common Side Effects (Temporary)

The following side effects are expected parts of the healing process and resolve in the majority of patients within 3 to 6 months:

Side Effect	Incidence	Typical Duration
Dry eye symptoms	20–40%	3–6 months (most cases)
Halos around lights	15–30%	1–3 months
Glare and starbursts	15–25%	1–3 months
Light sensitivity	20–30%	1–2 weeks
Fluctuating vision	20–40%	1–3 months
Foreign body sensation	Most patients	24–48 hours

Serious Complications (Rare)

Serious complications that result in permanent, significant vision loss are rare in properly screened patients. The following are the most clinically significant complications:

LASIK Risk Statistics

The following data is drawn from large-scale clinical studies and FDA-required post-market surveillance:

• Serious vision loss (worse than pre-operative corrected vision): less than 0.1%
• Clinically significant dry eye persisting beyond 6 months: 1–3%
• Halos/glare requiring intervention beyond 6 months: 1–2%
• Corneal ectasia (with modern topographic screening): less than 0.05%
• Flap-related complications: less than 0.5% with femtosecond technology
• Enhancement rate within 1 year: 2–5%
• Patient dissatisfaction at 12 months: approximately 1–5%

Dry Eye After LASIK

Dry eye is the most common LASIK complication and the primary reason some patients are not satisfied with their outcomes. LASIK severs corneal nerves during flap creation, temporarily reducing the eye's sensitivity and reflex tear production. In most patients, this resolves within 3 to 6 months as nerve regeneration occurs. In a small percentage, dry eye becomes chronic. Pre-existing dry eye significantly increases the risk. For a full discussion, see our dedicated page on dry eye after LASIK. Patients with significant dry eye at baseline may be better candidates for SMILE, which severs fewer corneal nerves.

Halos and Night Vision Problems

Halos, starbursts, and glare around lights — particularly oncoming headlights when driving at night — are common in the first 1 to 3 months after LASIK. They occur because the optical zone of the laser treatment creates a transition zone at the periphery. In most patients these symptoms diminish significantly as healing progresses. Persistent, bothersome night vision problems beyond 6 months occur in 1 to 2% of patients and may benefit from enhancement procedures or optical aids. See halos and glare after LASIK for full details.

Flap Complications

The corneal flap is unique to LASIK and creates both its key advantage (fast recovery) and a specific risk profile. Flap complications include incomplete or irregular flap creation, flap displacement from trauma, and striae (wrinkles in the flap). With femtosecond laser flap creation, these complication rates have been substantially reduced compared to microkeratome methods. Learn more about LASIK flap complications.

Corneal Ectasia

Corneal ectasia is the most serious LASIK-specific complication — a progressive weakening and forward bulging of the cornea that can cause significant vision deterioration. It occurs when too much tissue is removed or when a patient with undetected pre-existing corneal weakness undergoes LASIK. With modern topographic screening and conservative treatment planning, the incidence has fallen to less than 1 in 2,000 properly screened patients. Patients at risk for ectasia are better served by PRK or ICL.

How to Reduce Your LASIK Risk

The single most important risk-reduction strategy is thorough pre-operative screening. Choose a surgeon who invests in comprehensive evaluation technology including corneal topography, pachymetry, and wavefront analysis — not one who offers a 10-minute evaluation before scheduling surgery. The second most important factor is following post-operative instructions meticulously, particularly avoiding eye rubbing during the first month. Also review LASIK candidacy requirements and be honest about any symptoms of dry eye or history of corneal conditions. For a comparison with lower-risk alternatives, see LASIK vs PRK and LASIK vs SMILE.