Selection of an appropriate intraocular lens (IOL) and/or the applicable surgical parameters for optimizing the results of refractive procedures on the eye. Features of the IOL are crucial for the selection and/or adjustment of the optimal IOL, but so is the IOL selection method (and parameters) from a surgical perspective. For the method, corresponding output parameters are determined from predetermined, estimated, or measured input parameters and/or their mean values, wherein at least two input parameters are varied with one another and which have at least one input parameter as a distribution function. The resulting function is optimized by means of corresponding target values and the determined distribution function of one or more output parameters is used as a decision aid. The present solution is used for selecting an appropriate IOL and/or the applicable surgical parameters and is applicable in the field of eye surgery for implanting IOLs.