Optical design of low index intraocular lenses

The effect of shape of low index (1.43) intraocular lenses on optical performance of pseudophakic eyes was investigated. A range of image quality criteria was used. The optimum lens for on-axis vision was biconvex, with the more curved surface facing the cornea. For small off-axis angles, optimum lens shape varied with the ocular parameters. A recommended range of intraocular lenses is plano-convex (with the curved shape facing the cornea) to equi-convex. Compared with conventional poly(methyl methacrylate) lenses (1.492 index), optimum lens shapes of low index lenses were less sensitive to changes in eye parameters and lens fitting position. The magnitudes of aberration of pseudophakic eyes varied more with changes in lens shape and lens position in low index lenses than in conventional lenses.