How safe is LASIK over 3 to 5 years or more?
The evidence consistently shows that LASIK is safe and effective for the long term. In a study comparing LASIK and PRK for hyperopia (farsightedness), both procedures were deemed safe and effective at 3 years, with average refractive errors very close to zero (within 0.4 diopters of target) [1]. Another study on epi-LASIK for high myopia (nearsightedness) reported a safety index above 1.0 at every follow-up point over 3 years, meaning patients' best-corrected vision was as good or better than before surgery [4]. Similarly, a 45-month follow-up of LASEK and epi-LASIK found that 95% of eyes achieved 20/25 or better uncorrected vision, with safety indices of 1.01 and 1.02, respectively [5]. These numbers mean that, for the vast majority, vision is not only corrected but remains stable and safe over years.
What are the main long-term risks I should know about?
The most common long-term issue is refractive regression — a gradual return of some nearsightedness. One study found that after FS-LASIK, younger patients with thinner corneas were more prone to regression, and that this shift could worsen over time [2]. For very high myopia (over -10 diopters), regression was more pronounced, with only 19% of eyes staying within 1 diopter of the target at 3 years, compared to 82% for moderate myopia [4]. This means that if you have a high prescription, you may need a touch-up procedure years later. A much rarer but serious risk is traumatic flap displacement, where the corneal flap created during LASIK can be dislodged by an eye injury. In a large series of over 37,000 eyes, this happened in only 9 eyes (0.02%), and even then, surgical repositioning usually restored good vision [7]. Another case report describes a patient who suffered flap displacement 8 years after LASIK from a toy gun injury, but after treatment, vision returned to 20/20 [8]. So while the risk is real, it is extremely low and treatable.
Do different LASIK techniques affect long-term safety?
Yes, the type of laser and surgical approach can influence long-term outcomes, but all modern techniques appear safe. A study comparing two popular excimer lasers (MEL 90 vs. Schwind Amaris 750S) found no significant differences in safety or efficacy at 12 months, with no cases of serious complications like infection or corneal ectasia in either group [6]. However, flap-based techniques like LASIK have a different risk profile than flapless surface procedures like PRK or SMILE. One review notes that LASIK tends to cause more early dry eye and transient visual disturbances because the flap disrupts more corneal nerves, while SMILE, which uses a small incision without a flap, may have a lower risk of long-term corneal ectasia (a weakening of the cornea) [3]. For hyperopia, a study found that PRK induced slightly more astigmatism than LASIK at 3 years (13.3% of PRK eyes had >1 diopter of astigmatism vs. 0% for LASIK) [1]. So, while all methods are safe, your surgeon may recommend one over another based on your specific eye anatomy and prescription.
About These Sources
This answer is built on 8 peer-reviewed studies — published from 2012 to 2025, 1 from 2024 or later, 2 in Q1–Q2 journals — selected as the most relevant from 8 studies that passed quality screening, drawn from 41 papers retrieved from a database of over 500 million.
Sources used in this answer
Long-term results of hyperopic ablations using alcohol-assisted PRK and FS-LASIK: comparative study.
In a 3-year matched comparative study of 166 eyes, both alcohol-assisted PRK and FS-LASIK were safe and effective for hyperopia, though PRK induced slightly more postoperative astigmatism (13.3% of PRK eyes vs. 0% of LASIK eyes had >1 diopter of cylinder).
Analysis on the Correlation Between Long-term Refractive Regression and Visual Quality after FS-LASIK.
In a study of 153 eyes followed for more than 5 years after FS-LASIK, younger patients with thinner corneas were more susceptible to refractive regression, which could worsen over time, but regression was not linked to higher-order aberrations.
EARLY AND LATE COMPLICATIONS FOLLOWING VISION CORRECTION WITH SMILE AND LASIK METHODS. ANALYSIS OF DIFFERENCES
A 2025 review comparing SMILE and LASIK found that LASIK has higher rates of early dry eye and transient visual disturbances, while SMILE may offer better long-term corneal biomechanical stability and a lower risk of ectasia.
Long-term outcome of epi-LASIK for high myopia.
In a 3-year study of epi-LASIK for high myopia (33 eyes), safety indices were above 1.0 at all time points, but regression was significant for myopia over -10 D (only 18.75% within ±1 D at 3 years) versus moderate myopia (82.35% within ±1 D).
Long term results of Epi-LASIK and LASEK for myopia.
In a 45-month follow-up of 42 eyes, both LASEK and epi-LASIK were safe and effective for myopia, with 95% achieving 20/25 or better uncorrected vision and safety indices of 1.01 and 1.02, respectively.
One-Year Visual and Refractive Outcomes following LASIK for Myopia and Myopic Astigmatism with MEL 90 versus Schwind Amaris 750S Excimer Laser: A Comparative Study
In a 12-month study of 328 eyes undergoing LASIK with two different excimer lasers (MEL 90 vs. Schwind Amaris 750S), both showed comparable safety and efficacy, with no cases of flap complications, infection, or ectasia.
Traumatic Flap Complications After Femtosecond LASIK.
In a large retrospective series of 37,315 eyes, traumatic flap complications after femtosecond LASIK were very rare (0.02%, 9 eyes), and even complete flap avulsion had a favorable visual prognosis with minimal refractive change.
Management of traumatic displacement of LASIK flap
A case report describes a patient who suffered traumatic LASIK flap displacement 8 years after surgery; after flap repositioning with fibrin glue, uncorrected vision returned to 20/20 and remained stable at 8 months.