An intraocular lens assembly is disclosed that increases the positive spherical aberration of an eye in order to enhance both near vision and distance vision in the eye. The intraocular lens assembly comprises an intraocular lens that has a convex anterior surface and a concave posterior surface that increase the spherical aberration of the eye. The intraocular lens is constructed of a biologically compatible material. The intraocular lens may be used as a replacement for the crystalline lens of the eye. The intraocular lens may be placed within an anterior chamber or a posterior chamber of an a phakic eye or a phakic eye.