LASIK Risks and Side Effects: What to Know

Large-scale studies and FDA data consistently show that fewer than 1% of LASIK patients experience a significant complication. Patient satisfaction rates exceed 96% in most published surveys. These numbers reflect the maturity of LASIK as a procedure that has been refined over more than two decades of clinical use.

Because LASIK involves creating a thin corneal flap, there is a small risk of flap-related issues such as incomplete flaps, flap displacement, or wrinkles known as striae. Modern femtosecond lasers have significantly reduced these risks compared to older blade-based techniques. If a flap issue occurs, it is usually detected and corrected during the procedure or the immediate postoperative period.

Infection after LASIK is extremely rare, occurring in fewer than 1 in 5,000 cases. A condition called diffuse lamellar keratitis (DLK), sometimes referred to as 'sands of the Sahara,' involves inflammation under the flap. DLK is typically caught early at follow-up visits and responds well to steroid eye drops when treated promptly.

Many complications can be avoided through careful preoperative evaluation. Our refractive surgeon uses advanced corneal mapping and detailed measurements to identify patients who may be at higher risk. If your evaluation reveals concerns such as thin corneas, irregular corneal shape, or an unstable prescription, we will recommend alternative options that may be a better fit for your eyes.

Halos appear as soft rings of light around point light sources like headlights, while starbursts look like rays extending outward from those same lights. They occur because the treated zone on the cornea has a slightly different refractive power than the surrounding untreated area, which can scatter incoming light at the edges. Most patients notice these primarily when driving at night or in dimly lit environments, and they tend to diminish significantly within three to six months as the cornea heals.

Corneal ectasia is a progressive weakening and forward bulging of the cornea that can develop weeks to years after LASIK. It most commonly affects patients who had undetected corneal irregularities or insufficient remaining corneal thickness after the procedure. Prevention centers on rigorous preoperative screening with corneal topography and tomography scans, which map both the front and back surfaces of the cornea in detail. Patients who show early signs of corneal instability are not candidates for LASIK and are offered alternative vision correction options.

LASIK permanently reshapes the cornea, so the procedure itself cannot be undone. However, most complications are manageable with additional treatments. Residual refractive errors can be addressed with an enhancement, glasses, or contact lenses.

An enhancement is a follow-up laser procedure performed to refine your results if your initial correction was not fully on target. It is typically performed after your vision has stabilized, usually at least three to six months after the original surgery. You can read more about when enhancements are recommended on our LASIK enhancement page.

Modern LASIK is significantly safer than the earliest versions of the procedure. Key advances include the transition from blade-based flap creation to femtosecond lasers, the development of wavefront-guided and topography-guided treatment profiles, and improved eye-tracking systems that follow your eye movements in real time during surgery. Screening technology has also evolved, allowing surgeons to identify at-risk patients with much greater accuracy and prevent complications before they occur.

Consider asking about your personal risk profile based on your corneal thickness, pupil size, and prescription. Ask about the surgeon's complication and enhancement rates, as well as what technology is used for both flap creation and the laser correction. Patients considering LASIK after age 40 should also discuss how presbyopia may influence their long-term results.