Extended Depth of Focus Lenses: A Continuous Range of Vision

How EDOF lenses work

Instead of directing light to two or three separate points, an EDOF lens elongates the focal zone, using either a diffractive pattern tuned to spread focus or a non-diffractive optic that transitions smoothly across the lens. The result is one continuous range of clear vision rather than a set of discrete distances, which the brain finds easier to use and which avoids the rings of light that multifocal patients see around headlights.

What patients can expect

Distance vision comparable to a monofocal. Excellent intermediate vision at arm's length, for computers, cooking, dashboards and phones held normally. Near vision that is functional for most everyday reading and that many patients find sufficient, with light readers kept for small print, long books or dim light. Night vision with minimal halos and good contrast. The result is often described as the most natural of the premium lenses.

EDOF versus multifocal

The choice is between near vision and night vision. A trifocal gives sharper reading at the cost of more halos; an EDOF gives cleaner night vision at the cost of some reading independence. Blended EDOF, with the non-dominant eye set slightly nearer, narrows the gap, and is a common way to get both. Your surgeon will ask about your night driving, your reading habits and your tolerance for glare, and recommend accordingly.

Who suits EDOF lenses

• Patients who drive at night or are sensitive to glare
• Screen based workers who want intermediate vision above all
• Patients with mild macular changes or a slightly irregular cornea, who may tolerate non-diffractive EDOF optics better than multifocal ones
• Patients who have had LASIK, where non-diffractive EDOF designs are often more forgiving of residual aberrations
• Anyone who wants a broad range of vision but does not mind readers for fine print