The present invention relates to a method of determining the IOL refractive index for an ocular replacement material for replacing tissue in the capsular bag comprising combining a neutral (non-correcting) reference refractive index ("NRRI") of between 1.421 and 1.450 with a refractive index correction factor ("RICF") ascertained by reference to the refractive power required to correct the patient's refractive error. The present invention also relates to methods of treating presbyopia, myopia and hyperopia using the above method.
