optimisation strategies amongst each other. due to considerable confusion in the past, a clear set of guidelines now exists to report iol power related data. there are six key measures that are to be reported. in recognition of the fact that comparison of ideal iol powers is likely to be error-prone, all comparisons are done for actual or predicted refractive errors. 1. mean error (me) and standard deviation (sd) in prediction. 2. mean absolute error (mae) and standard deviation (sd) in prediction. 3. the percentage of eyes ± 0.5 d from the predicted target refraction. 4. the percentage of eyes ± 1.0 d from the predicted target refraction. 5. the percentage of eyes > 2.0 d from the predicted target refraction. 6. range of errors from maximum plus error to maximum minus error. software tools can be used in order to perform an audit.