The optical design of intraocular lens implants.

Intraocular lens implants have been around for more than 25 years. On the verge of a major breakthrough to ever widening popularity, there is, however, a general lack of understanding of the pertinent optical principles. A critical comparison is made between this new method and conventional methods of correcting aphakia. From this it appears that the visual needs of the patient are a decisive factor in the selection of the method of correction. Moreover, the full potential of intraocular lens implants can only be realized by appropriate selection of the power of the implant in each situation. To this end, ultrasonic measurement of the ocular axial length is indispensable. The use of standard power lens implants is inadequate. Formulas are presented to make an eye emmetropic or to give it any refractive error. Guidelines are given for the use of these formulas. Two methods for obtaining equal image size in unilateral antiphakia are described.