Custom Wavefront LASIK, Explained

What a wavefront map shows

A glasses prescription describes the eye with three numbers: sphere, cylinder and axis. Real eyes are more complicated. Light passing through the cornea and lens picks up small irregularities, called higher order aberrations, that a prescription cannot describe and glasses cannot correct. They are the reason two people with the same prescription can see differently at night, and why some people notice halos and starbursts around headlights.

A wavefront aberrometer sends a low energy light into the eye and measures the shape of the wave that returns. The result is a map of every optical error in the eye, lower and higher order, at hundreds of points across the pupil. Custom wavefront LASIK uses that map to shape the treatment.

How the treatment differs from conventional LASIK

Conventional LASIK removes tissue in a pattern derived from the prescription, the same pattern for everyone with those numbers. Wavefront guided LASIK removes tissue in a pattern derived from your map, so it treats the aberrations your eye actually has. The steps in the laser suite are identical: numbing drops, a femtosecond flap, the excimer treatment and the flap laid back. Only the pattern the excimer follows is different.

Wavefront optimized treatments are a related approach: they keep the cornea's natural shape as tissue is removed, which limits the aberrations the surgery itself might induce. Your surgeon discusses which profile suits your measurements at the consultation.

Who gains the most from a custom treatment

The difference is most noticeable in patients who:

• Have larger pupils in dim light, where higher order aberrations have the greatest effect
• Drive at night for work or notice halos and glare around lights already
• Have a measurable amount of higher order aberration on their wavefront map
• Want the sharpest possible contrast sensitivity, not only a 20/20 letter chart result

Patients with very regular optics gain less, and your surgeon will explain at the consultation whether a custom profile adds value for your eyes.

What the evidence shows

Wavefront guided and wavefront optimized LASIK have been compared in many clinical studies. Both give excellent uncorrected vision. Where they differ is in the quality of vision: custom treatments tend to induce fewer new aberrations and give better contrast sensitivity and night vision than older conventional profiles. Results vary from patient to patient, and your surgeon will tell you what your own map predicts.