In one aspect, the present invention provides a method of designing an intraocular lens (IOL) to address variations of at least one ocular parameter in a population of patient eyes. The method can include establishing at least one eye model in which the ocular parameter can be varied over a range exhibited by the population. The eye model can be employed to evaluate a plurality of IOL designs in correcting visual acuity for eyes in the patient population. An IOL design that provides a best fit for visual performance over at least a portion of the parameter range can then be selected.