Quick Answer
The most common LASIK side effects are dry eye (affects 20–55% of patients short-term), halos and glare around lights (affects 15–20%), and light sensitivity. The majority of these resolve within 3–6 months. Rare side effects include persistent dry eye beyond 12 months, significant night vision disturbances, and corneal ectasia (less than 0.1% of properly screened patients). Permanent, vision-threatening side effects are uncommon in correctly selected candidates.
Detailed Explanation
A clear-eyed understanding of LASIK side effects requires separating what is common and temporary from what is rare and potentially lasting. Both categories deserve honest discussion.
Common and typically temporary side effects
Dry Eye (most common)
Dry eye is the most frequently reported LASIK side effect. It occurs because LASIK severs corneal nerve fibers during flap creation, temporarily reducing the eye’s ability to sense when it needs tears and signal tear production.
- Incidence: 20–55% of patients experience noticeable dry eye in the weeks after surgery
- Duration: Most cases resolve within 3–6 months as nerve fibers regenerate
- Symptoms: Grittiness, burning, foreign body sensation, intermittent blur, light sensitivity
- Management: Preservative-free lubricating drops (used frequently), omega-3 supplementation, punctal plugs for persistent cases, prescription dry eye medications (cyclosporine, lifitegrast) in moderate-to-severe cases
Patients with pre-existing dry eye are at higher risk for more severe and prolonged post-operative dryness. Aggressive pre-operative identification and management of dry eye disease is one of the most important things a practice can do to protect patients.
Halos and Glare
The healing cornea produces optical aberrations that manifest as halos around lights, starburst patterns, and glare — most pronounced at night and in low-light conditions.
- Incidence: 15–20% of patients report significant halos/glare in the first weeks
- Duration: Improves substantially within 3 months for most patients; largely resolved by 6 months
- Contributing factors: Larger pupil size relative to ablation zone, higher prescriptions, wavefront-guided vs. conventional treatment
Modern topography-guided and wavefront-guided treatments produce fewer higher-order aberrations than conventional LASIK, making current-generation procedures significantly better than older LASIK for night vision outcomes.
Light Sensitivity (Photophobia)
Common in the first 24–72 hours; typically resolved or substantially reduced within 1–2 weeks. Wearing quality sunglasses with UV protection is recommended during daylight hours in the first weeks.
Blurry or Fluctuating Vision
Vision fluctuates during the healing process — clearer in some moments than others, and often better in the morning before eyes tire. This typically stabilizes within 1–3 months.
Foreign Body Sensation
A feeling of something in the eye is common in the first few days as the epithelium heals at the flap margin. Lubricating drops provide relief; rubbing should be strictly avoided.
Subconjunctival Hemorrhage
Small red spots on the white of the eye caused by the suction ring during flap creation. Harmless, resolve within 1–2 weeks without treatment. Alarming in appearance but medically insignificant.
Uncommon and potentially lasting side effects
Persistent Dry Eye Disease
A subset of patients — estimated at 5–10% — develops dry eye that persists beyond 6 months and requires ongoing management. Risk factors include pre-existing dry eye, female sex, autoimmune conditions, and hormone fluctuations. Long-term management options exist and can effectively control symptoms, but this should be discussed transparently before surgery.
Persistent Night Vision Disturbances
A small percentage of patients — particularly those with larger pupils or higher prescriptions treated with older laser platforms — experience halos and glare that do not fully resolve. Current-generation wavefront and topography-guided treatments have substantially reduced this risk, but not eliminated it. If you frequently drive at night or work in low-light environments professionally, this is worth an explicit pre-operative discussion.
Regression
Some patients experience a gradual return of myopia over years. Treatable with enhancement surgery in most cases if corneal thickness allows.
Corneal Ectasia (rare)
Progressive thinning and irregular bulging of the cornea after LASIK. Almost exclusively occurs in patients with undetected keratoconus or insufficient residual stromal tissue. Incidence is less than 0.04% in properly screened patients. This is why advanced corneal tomography — not just topography — is essential before surgery.
Under/Overcorrection and Irregular Astigmatism
Refractive errors that persist after surgery. Most undercorrections are treatable with enhancement surgery. Irregular astigmatism caused by flap complications or decentered ablations can produce symptoms not correctable with glasses or standard contacts.
The practices recognized by LASIK Surgery Awards are evaluated on their pre-operative screening rigor — because the best way to manage serious side effects is to screen out the patients at highest risk before surgery.
Important Considerations
Most patients do not experience significant lasting side effects. The 96% satisfaction rate reported across large studies reflects a reality where most patients heal well, achieve their visual goals, and would recommend the procedure. The side effect profile presented here is comprehensive — it does not reflect the typical patient experience.
Your pre-existing conditions affect your risk profile. Patients with pre-existing dry eye, large pupils, high prescriptions, autoimmune conditions, or irregular corneas face a higher risk of certain side effects. These patients require more detailed pre-operative counseling, not necessarily disqualification.
Side effect management has improved substantially. The dry eye and halos that were genuinely problematic in early LASIK cohorts (late 1990s and early 2000s) are far less severe with current technology and management protocols.
What to Do Next
1. Discuss your personal risk factors for specific side effects with your surgeon — dry eye history, pupil size, prescription magnitude, and prior corneal issues all affect your individual profile. 2. Ask about your surgeon’s management protocol for dry eye: what drops, what follow-up schedule, and what escalation options exist. 3. If night vision is critical to your livelihood — pilots, truck drivers, surgeons — have a detailed discussion about the probability of night vision disturbances and whether they can be mitigated.
For a broader look at safety data across LASIK outcomes, see Is LASIK Eye Surgery Safe?.
Related Questions
Concerned about the most serious possible outcome? Read Can You Go Blind from LASIK? for a fact-based examination of the worst-case scenarios.
Wondering about specific side effects during and immediately after surgery? See Does LASIK Hurt During or After the Procedure? for the immediate post-operative experience.
Trying to assess whether LASIK’s side effect profile is better or worse than SMILE? Read What Is the Difference Between LASIK and SMILE? for a direct comparison.