Optical design of intraocular lenses. III. On-axis performance in the presence of lens displacement.

The effect of intraocular lens shape on on-axis performance of model pseudophakic eyes was investigated, when lenses were displaced by tilting or decentration. Image quality criteria included an optimization procedure, spot diagrams, and the modulation transfer function (MTF). Displacement adversely affects image quality. With conventional lens shapes, the deterioration is either small or retinal image quality can be nearly restored to predisplacement levels by spectacle correction. Optimum lens shapes in the presence of decentration are close to being plano-convex, with the more curved surface facing the cornea. Based on the results of this and previous studies, it is suggested that preferred shapes of intraocular lenses range from this plano-convex form to equi-convex.