This article is designed to help the ophthalmologist evaluate the advantages and disadvantages of the various intraocular lens optic configurations now available. The optical and mechanical requirements of intraocular lenses are described and the concepts behind these requirements are explained. A Table rates the performances of five optic configurations (convexo-plano, plano-convex, biconvex, meniscus, asphero-plane) in meeting optical and mechanical requirements.