The clinical use, accuracy, and reliability of the Veri-Vu lensometer.

One hundred forty-six lenses from 11 manufactures were tested with the Veri-Vu lensometer and optical power plus resolution compared with results from an optical bench. Accuracy was found to be +/- 0.2 diopter in 95% of the lenses tested. The greatest error was 0.37 D. The lensometer correctly identified 125 of 128 lenses that were greater than 160 line pairs per millimeter (LP/mm) resolution and correctly identified nine lenses that had less than 100-LP/mm resolution. All other important optical aberrations were identified with the lensometer. The greatest problem was the variation from company to company in terms of the calculated power in aqueous as determined from the back focal length in air. This, however, was felt to be an asset for those doing A-scan intraocular lens power determination in giving one simple reliable power for all lens companies.