Intraocular lens optical quality: update 1979.

One hundred and twenty lenses from 12 manufacturers were randomly selected for optical studies using an optical bench. Resolution efficiency was measured with an Air Force target, and measurements of back focal length in air were used to calculate back focal length in aqueous. There were no lenses with: less than 50% resolution efficiency, more than a 0.5-D variation from the stated power, or more than 0.25 D of toricity. Seventy-five percent of the lenses had at least 74% resolution efficiency; 93% were within 0.25 D of the stated power; 95% had 0.1 D or less toricity. Lenses of recent manufacture exhibit a marked improvement in optical quality. Optical parameters for all lenses observed in this study were within good clinical ranges.