The present invention provides an intraocular lens (IOL) having an optic with a posterior and an anterior refractive surfaces, at least one of which has an aspherical profile, typically characterized by a non-zero conic constant, for controlling the aberrations of a patient's eye in which the IOL is implanted. Preferably, the IOL's asphericity, together with the aberrations of the patient's eye, cooperate to provide an image contrast characterized by a calculated modulation transfer function (MTF) of at least about 0.25 and a depth of field of at least about 0.75 Diopters.