Rigid and foldable intraocular lenses of various materials have shown light scattering phenomena such as surface light scattering and glistenings. The impact of these phenomena on visual function is under controversial discussion. The scattering of light in an IOL can be measured in various ways. In many studies, subjective grading at the slit-lamp has been used to quantify the intensity of scattering. More recently, evaluation of high-resolution digital Scheimpflug images has been able to provide an objective assessment of scatter and material inhomogeneities. Better quantification of these phenomena may achieve more meaningful correlations to results of functional measurements.