The evaluation of optical surface defects is an integral part of the realization of precise optical elements. In addition to the traditionally used visual inspection procedures based on MIL-O-13830A, procedures based on ISO standards, which underwent some changes in 2017, are coming to the forefront. One of these changes was the omission of equivalent radiometric sizes and their replacement by geometric dimensions. This paper focuses just on the analysis of the impact of this change on the values of specifications defining the requirements on the scratch and dig quality of optical elements. Among other things, this presents a possible way to correct specification classes based on the statistical processing of a set of parameters of imperfections detected on optical element surfaces, which have been realized in the TOPTEC Centre.