INTRAOCULAR-LENS PERFORMANCE IN AIR, IN WATER, AND IN-SITU - A COMPUTER STUDY

Computer analysis is used to predict performance of four intraocular l enses with assigned values of aberration. Cylinder error and aspherici ty error are used as examples of possible manufacturing errors. Three measures of performance are calculated: maximum optical path differenc e, root mean square optical path difference, and modulation transfer f unction. For evaluation in air these standard test conditions are assu med: collimated green light incident on the convex surface of a plano- convex lens, with a 3 mm aperture. All four lenses show substantially improved performance in water compared to air, and a further improveme nt in the simulated eye (i.e., in situ). However, an aberrated 30 diop ter (D) lens with performance in air comparable to an aberrated 20 D l ens, performs worse in situ than does the 20 D lens. This suggests tha t a performance test in air that is suitable for a 20 D lens (e.g., 10 0 line pairs per millimeter resolution) may not be adequate for a 30 D lens. A test in air at 30% resolution efficiency may be more suitable .