Shammas HJ, Shammas MC, Jivrajka RV, et al. - In this single-arm, non-interventional, non-randomized retrospective chart review, researchers sought to compare axial length measurements based on multiple specific refractive indices for each segment of the eye to those obtained utilizing a single refractive index for the entire eye and to assess the subsequent effects on IOL power calculation. Eyes undergoing cataract surgery where biometry and IOL power calculations were based on axial length calculated with multiple specific refractive indices (multiple) have been assessed. In total, 595 eligible eyes have been assessed. Differences were noted, primarily in the short and long eyes, between axial lengths measured using a single refractive index and multiple refractive indices. Differences had an effect on the calculation of IOL power. As the precision of formulas increases, such effects can become increasingly important.