The effect of poly(methyl methacrylate) intraocular lens shape on optical performance of pseudophakic eyes was investigated. Image quality criteria included wave aberrations, spot diagrams, longitudinal aberrations, the modulation transfer function, and an optimization procedure. For eyes with corneal asphericities encompassing most of the population, the optimum lens form for on-axis vision is close to plano-convex, with the more curved surface facing the cornea. This applies whether lenses are correctly centered, tilted, or decentered. For small off-axis angles, optimum lens shape varies with the ocular parameters. Good intraocular lens shapes range from the plano-convex to the equi-convex. Plano-convex lenses with the curved surface facing the retina are not recommended.