Introduction
Every elective surgical procedure carries risks, and LASIK is no exception. The procedure permanently alters the corneal architecture, and no amount of technological sophistication or surgical skill can eliminate risk entirely. Patients who approach LASIK with an accurate, complete understanding of the risk profile are better positioned to give meaningful informed consent, manage their post-operative expectations, and recognize when they need additional clinical attention.
What patients deserve — and what the LASIK Surgery Awards program expects of recognized practices — is honest, complete disclosure of the risk picture. Not a minimizing sales narrative. Not a dismissive “the risks are very small, don’t worry about it.” A genuine accounting of what can go wrong, how frequently it occurs, how serious it is, and how it is managed.
This page provides exactly that. It covers every major LASIK risk and complication category: how common each is in the published literature, what causes it, how it is managed, what its long-term implications are, and — importantly — which of these risks can be meaningfully reduced by excellent surgeon selection and rigorous pre-operative screening. The goal is not to alarm patients but to give them the complete picture they need.
Section 1: Common Post-Operative Symptoms — Mostly Transient
The Distinction Between Expected Side Effects and True Complications
Before examining true complications, it is important to distinguish between expected post-operative symptoms — which are nearly universal, temporary, and self-resolving — and genuine complications, which are less common, potentially persistent, and may require intervention.
Dry Eye
Post-LASIK dry eye is the most commonly reported post-operative complaint. It occurs because the creation of the LASIK flap severs corneal nerves that regulate reflex tear secretion. As a result, the reflex that triggers tear production in response to corneal irritation is temporarily impaired, leading to reduced natural tear volume and the associated symptoms of dryness, foreign-body sensation, blurred vision, and light sensitivity.
Published incidence of clinically significant post-LASIK dry eye ranges from approximately 20% to 55% at one month post-operatively, depending on population, diagnostic criteria, and the instruments used for assessment. Most cases resolve within three to six months as corneal nerve density recovers. Roughly 3% to 5% of patients experience persistent dry eye symptoms beyond twelve months.
Risk factors for more significant and prolonged dry eye include female sex, older age, higher prescription (requiring a larger ablation zone), pre-existing dry eye disease, and the use of LASIK versus SMILE or PRK (both of which preserve more corneal nerve density). Rigorous pre-operative dry eye screening — a hallmark of safety-conscious practices — identifies patients at elevated risk and enables pre-operative optimization of tear film health.
Management options include preservative-free artificial tears, punctal occlusion, prescription anti-inflammatory drops (cyclosporine, lifitegrast), meibomian gland therapy for lipid-deficient tear film, and dietary omega-3 supplementation.
Glare, Halos, and Starbursts
A significant proportion of patients report new or worsened visual symptoms in low-contrast or nighttime conditions after LASIK — typically described as halos around lights, starbursts radiating from point sources, or glare in oncoming headlight situations. These symptoms are related to aberrations created at the edge of the ablation zone and the flap-cornea interface.
In clinical series using current-generation wavefront-guided treatments, approximately 20% to 30% of patients report some degree of new nighttime visual symptoms in the first three months post-operatively. Most improve significantly over six to twelve months as the corneal surface stabilizes and the nervous system adapts. Fewer than 5% of patients in most large series report persistent, bothersome nighttime symptoms at twelve months.
Patients with large scotopic pupils relative to the treatment optical zone are at higher risk. Wavefront-guided treatments, which optimize the quality of the ablation profile across the treatment zone, are associated with lower rates of quality-of-vision complaints than conventional treatments.
Visual Regression
A gradual return of some refractive error — particularly myopia — can occur over the years following LASIK. Regression is more common with higher initial prescriptions and may require glasses or contact lens correction for certain activities (typically night driving or other high-contrast visual demands) years after a successful procedure.
Most patients with significant regression at any time point remain candidates for an enhancement procedure, subject to adequate residual corneal tissue for additional ablation.
Section 2: Less Common But Significant Complications
What Requires Clinical Attention and How It Is Managed
Beyond the common transient symptoms, a range of less frequent but more significant complications can occur after LASIK. Awareness of these complications, their warning signs, and their management options is important for informed consent.
Flap Complications
The LASIK flap — created by the femtosecond or microkeratome cut — represents a potential vulnerability in the corneal architecture. Flap complications include:
- *Flap striae* (wrinkles in the flap): These can cause visual distortion and typically require the flap to be lifted and smoothed. Most are managed successfully in the early post-operative period.
- *Flap displacement*: Caused by eye rubbing, trauma, or other mechanical force to the eye. The displaced flap requires same-day repositioning. Risk is highest in the first 24 to 72 hours and significantly diminishes over weeks as the flap heals in position.
- *Epithelial ingrowth*: Growth of surface epithelial cells under the flap edge. Minor ingrowth often resolves spontaneously; significant ingrowth that affects the visual axis may require the flap to be lifted and the cells removed.
In aggregate, flap-related complications requiring intervention occur in approximately 1% to 2% of procedures in published series, with the majority manageable to excellent outcomes when addressed promptly.
Diffuse Lamellar Keratitis (DLK)
DLK — commonly called “Sands of the Sahara” — is a sterile inflammatory reaction in the interface between the flap and the underlying stroma. It typically presents in the first one to five days post-operatively as a diffuse, fine, sand-like haze in the flap interface.
The incidence of DLK in published series ranges from approximately 1% to 3% of procedures. When caught early and managed appropriately with intensive topical corticosteroids and close monitoring, most cases of DLK resolve without affecting the final visual outcome. Advanced or delayed-treatment cases can affect vision more significantly.
DLK is a key reason why the day-1 post-operative visit is not optional — its early identification at the slit lamp is the most reliable way to initiate prompt treatment.
Infection (Infectious Keratitis)
Bacterial, fungal, or acanthamoeba infections of the flap interface are rare (estimated at 0.02% to 0.2% of procedures) but serious. Interface infections can be difficult to treat due to limited antibiotic penetration through the flap, and severe or delayed-treatment cases can result in permanent corneal scarring and vision loss.
Prevention through rigorous sterility protocols, antibiotic prophylaxis, and patient compliance with post-operative activity restrictions (particularly avoidance of water exposure in the first two weeks) is the most effective approach. Any patient who develops increasing pain, redness, photophobia, or vision loss after an initial period of normal recovery should contact their practice urgently.
Post-LASIK Ectasia
Post-LASIK ectasia is the most serious non-infectious complication of the procedure. It involves a progressive thinning and steepening of the cornea after LASIK that resembles keratoconus. When significant, it can result in irregular astigmatism, markedly degraded vision, and ultimately the need for corneal transplantation in severe cases.
The published incidence of post-LASIK ectasia is estimated at 0.04% to 0.6% — low in absolute terms, but significant given its severity. The primary risk factor is undetected or underappreciated pre-existing corneal ectasia — particularly forme fruste keratoconus — at the time of the initial surgery.
Rigorous pre-operative corneal tomography is the most powerful available tool for identifying patients at elevated ectasia risk before they undergo surgery. Management of established post-LASIK ectasia has improved substantially with the introduction of corneal collagen cross-linking (CXL), which can halt the progressive thinning process when applied early. Rigid contact lens fitting, intrastromal ring segments, and in severe cases, keratoplasty (corneal transplantation) are additional management options.
See Patient Safety Standards in Award-Winning LASIK Practices for detail on how top practices screen for ectasia risk pre-operatively.
Section 3: How Top Surgeons Minimize Complication Risk
Prevention Through Screening, Technique, and Technology
The meaningful reduction of LASIK complication risk is not primarily about luck or genetics — it is about systematic, evidence-based risk reduction through every phase of the surgical process.
Screening Rigor
The single most impactful complication prevention measure is the thoroughness of pre-operative screening. Specifically: detecting pre-existing dry eye disease and managing it before surgery; identifying corneal irregularities that indicate ectasia risk; calculating residual stromal bed depth accurately and conservatively; and identifying systemic conditions that elevate wound healing or infection risk. Award-winning practices treat screening as the primary safety gate it is, rather than as a formality preceding the inevitable surgical plan.
Technology Selection
Femtosecond laser flap creation produces more consistent, customizable flap architecture than microkeratome-based flap creation and is associated with lower rates of flap complications in most large series. Wavefront-guided treatments reduce the risk of quality-of-vision complaints compared to conventional treatments. Equipment calibration and maintenance protocols ensure that delivered treatments match planned parameters.
Intraoperative Vigilance
Top surgeons apply the same attentiveness intraoperatively that they bring to screening. If the eye fails to track properly during the laser application, they pause. If the flap architecture appears irregular during assessment, they address it before proceeding. If any unexpected finding emerges during the procedure, they prioritize patient safety over operative efficiency.
Post-Operative Monitoring
Early complication identification requires regular post-operative follow-up, and patients who adhere to their follow-up schedule fare better when complications do occur. Award-winning practices implement structured recall systems to ensure patients are not lost to follow-up — because the surgeon who never sees a patient post-operatively cannot identify developing complications early.
For a broader view of what safety-conscious practices look like, review LASIK Surgery Awards and the recognition criteria applied to program participants.
Section 4: What Patients Should Understand Before Consenting
Risk Communication and Realistic Expectations
Informed consent in LASIK is a genuine communication process, not a stack of papers to sign before entering the operating room. Patients who understand the risk picture fully — including the specific risk factors most relevant to their anatomy and health status — are in a position to give genuinely meaningful consent.
Ask About Your Personal Risk Profile
Rather than asking “Is LASIK safe?” — which will inevitably produce a generic reassuring answer — ask: “What are the specific risks most relevant to my situation?” If you have pre-existing dry eye, ask specifically about post-operative dry eye risk. If your prescription is high, ask about regression and enhancement likelihood. If you have borderline topography, ask specifically what it shows and what it means for your ectasia risk.
Understand the Complication Response Process
Before consenting to surgery, understand what happens if you develop a complication. Who will you contact? How quickly will you be seen? Who performs the complication management? A surgeon who is forthcoming with this information is demonstrating the transparency that characterizes a genuinely patient-centered practice.
Weigh the Risks Against the Alternatives
LASIK risks exist, but they should be weighed against the risks and limitations of the alternatives: contact lens-associated infections and complications (estimated annual incidence of microbial keratitis from contact lenses approaches 1 in 500 extended-wear users per year), the lifestyle restrictions of spectacles, and the cost and inconvenience of continued refractive correction. For many patients, the risk-benefit calculation strongly favors LASIK — but that calculation should be made with complete information.
See LASIK Candidacy: Who Qualifies for the Procedure for guidance on which patient populations carry the highest and lowest risk profiles. For context on how risk compares to overall outcome quality, review LASIK Surgery Success Rates and What They Mean.
Frequently Asked Questions
Q: What is the most serious risk of LASIK? Post-LASIK ectasia is the most serious non-infectious complication, with potential for progressive and difficult-to-manage vision loss. It is largely preventable through rigorous pre-operative corneal topography and tomography screening. Infectious keratitis, while rare, can also cause serious and permanent vision damage if not caught and treated promptly.
Q: Will LASIK cause permanent dry eye? Most post-LASIK dry eye resolves within three to six months. A small percentage of patients — estimated at 3% to 5% — experience persistent dry eye symptoms beyond twelve months. Patients with pre-existing dry eye disease face elevated risk of more significant and prolonged post-operative dry eye.
Q: Is LASIK FDA approved as safe? LASIK is FDA-approved, and the FDA has determined that the procedure’s benefits outweigh its risks for appropriate candidates. The FDA’s PROWL studies, conducted in 2013 and 2014, provided important nuance by documenting the full spectrum of patient-reported outcomes including visual symptoms.
Q: Can complications be corrected after LASIK? Many LASIK complications can be effectively managed or corrected. Flap complications, DLK, regression, and most quality-of-vision symptoms respond to appropriate treatment. Post-LASIK ectasia can be stabilized with cross-linking and managed with specialty contact lenses or surgical intervention. The management outcome depends heavily on how quickly the complication is identified and addressed.
Next Steps
Understanding LASIK risks honestly is not a reason to avoid LASIK — for the right patient, with the right surgeon, the procedure is remarkably effective and safe. It is a reason to choose your surgeon carefully, participate actively in your pre-operative evaluation, and adhere rigorously to your post-operative care plan.
The LASIK Surgery Awards program recognizes surgeons and practices that apply the screening rigor, technology standards, and patient communication practices that minimize preventable LASIK complications. Find top-evaluated providers in your area through the program directory.
*Complication rates cited on this page are derived from peer-reviewed published literature. Individual risk profiles depend on patient-specific anatomy and health factors.*