LASIK can affect night vision, and it’s one of the most common side effects people experience after surgery. Up to 46 percent of patients who had no visual symptoms before LASIK reported at least one new symptom three months after surgery, according to an FDA quality-of-life study. The good news: most night vision issues improve significantly within the first year, and fewer than 1 percent of patients find that symptoms seriously interfere with daily life.
What Night Vision Changes Look Like
Night vision disturbances after LASIK fall into a few distinct categories. Halos are soft rings of light that appear around headlights, streetlights, or any bright point source in the dark. Starbursts look like spikes or rays radiating outward from lights. Glare is a general wash of brightness that makes it harder to see clearly, and ghosting produces faint double images. Some people also notice reduced contrast sensitivity, meaning objects in dim light look flatter or harder to distinguish from their background.
Halos are the most frequently reported symptom. The FDA’s LASIK Quality of Life Collaboration Project found that up to 40 percent of participants who had no halos before surgery developed them within three months. These symptoms tend to be most noticeable while driving at night, when oncoming headlights and traffic signals create the exact conditions that trigger them.
Why LASIK Changes How You See in the Dark
Your pupils expand in low light to let in more of it. When they do, light passes through a larger area of your cornea, including the edges of the zone reshaped during surgery. That boundary between treated and untreated corneal tissue scatters incoming light, creating halos and starbursts.
LASIK also introduces subtle irregularities in the cornea’s surface called higher-order aberrations. Research in the International Journal of Ophthalmology has shown that specific types of these irregularities, particularly a pattern called vertical coma, are the main factor reducing contrast sensitivity at a pupil size of 6 mm (a typical size in dim conditions). It’s not the total amount of irregularity that matters most, but the specific pattern. This is why two patients with similar prescriptions can have very different night vision outcomes.
Who Is Most at Risk
The strongest predictor of night vision complaints is how much correction LASIK needs to make. A study of nearly 1,500 eyes found that patients correcting more than 5 diopters of nearsightedness were 2.8 times more likely to report night vision problems at one year than those with lower prescriptions. A smaller optical zone (the diameter of the reshaped area on the cornea) increased risk by 2.5 times when it was 6.0 mm or smaller. And patients whose final prescription landed more than half a diopter away from perfect vision had 2.9 times the risk.
Patient age also played a significant role throughout the first postoperative year. Interestingly, that same large study found that pupil size was not a statistically significant predictor of night vision complaints once other factors were accounted for, though a separate study did find a correlation between large pupils measured before surgery and subjectively worsened night vision. The relationship between pupil size and symptoms is debated, but prescription strength and optical zone size are consistently the strongest risk factors.
How Symptoms Change Over Time
Night vision disturbances are most intense in the first weeks after LASIK and improve steadily. In the study of nearly 1,500 eyes, 25.6 percent of patients reported night vision complaints at one month. By 12 months, that number had dropped to 4.7 percent. UCLA Health’s postoperative guidance notes that vision fluctuation and halos around lights at night are normal for the first month or more, with full stabilization taking several months.
The early intensity of symptoms doesn’t necessarily predict the long-term outcome. Much of the initial disturbance comes from temporary swelling and the healing corneal flap, which gradually clears. The brain also adapts to mild residual aberrations over time, a process called neural adaptation, which further reduces how much you notice remaining symptoms.
Wavefront-Guided LASIK Makes a Difference
Not all LASIK procedures carry the same risk. Wavefront-guided LASIK, which maps the eye’s unique optical imperfections and customizes the laser treatment accordingly, performs significantly better for night vision than conventional LASIK.
A study comparing the two approaches in patients with moderate nearsightedness (around negative 5 diopters) found striking differences in simulated night driving performance. After conventional LASIK, patients lost an average of 21 to 28 feet of recognition distance for road signs and hazards at night. After wavefront-guided LASIK, patients actually gained 15 to 29 feet. Clinically meaningful losses in night driving performance occurred in 32 to 38 percent of conventional LASIK eyes, compared to 0 to 3 percent of wavefront-guided eyes. In fact, 11 to 31 percent of wavefront-guided patients showed measurable improvement in night vision over their pre-surgery baseline.
Most LASIK practices today use wavefront-guided or wavefront-optimized platforms as their standard, which is a major reason night vision complaints have declined compared to earlier generations of the procedure.
Living With Post-LASIK Night Vision Symptoms
For the small percentage of patients who experience persistent symptoms, several practical strategies help. Anti-reflective coated glasses worn specifically for night driving reduce glare. Some patients benefit from a mild prescription in night-driving glasses even if their daytime vision is excellent, because correcting a tiny residual refractive error can meaningfully reduce halos. Pupil-constricting eye drops are occasionally used before night driving to limit how much light enters through the peripheral treatment zone, though this is less common.
If symptoms remain bothersome beyond 12 months, a follow-up evaluation can determine whether a retreatment or enhancement procedure would help. Specialty contact lenses that mask corneal irregularities are another option for the rare cases where retreatment isn’t suitable. The FDA’s study found that less than 1 percent of participants experienced “a lot of difficulty” with or inability to perform usual activities because of any single visual symptom after LASIK, so truly debilitating long-term outcomes are uncommon.