As medical technology continues to advance and people's quality of life continues to rise, cataract surgery has transitioned from the conventional period of blindness restoration surgery to the era of refractive surgery. Multifocal intraocular lenses (MIOLs) have been accepted and recognized by an increasing number of doctors and patients as a result of the development of numerous new functional intraocular lenses (IOLs) that have allowed patients to escape the limitations of glasses to varying degrees [1], [2], [3]. However, compared to monofocal IOLs, the influence of the patient's angle kappa, angle alpha, corneal spherical aberration, and other factors on their visual quality is significantly larger due to the vast range of MIOLs with various optical characteristics. If MIOLs are not specifically chosen for each patient before surgery in accordance with their ocular characteristics, they will not only be unable to achieve good whole-course visual acuity but will also result in visual disturbances like a decrease in contrast sensitivity, glare, and halo, which will have an impact on the patient's postoperative satisfaction [4,5].Therefore, accurate and reliable preoperative examination and comprehensive and effective preoperative evaluation are particularly crucial.

OPD-Scan III and Pentacam both visually provide all the parameters required for the individualized selection of patients for implantation of multifocal IOLs, but there are only a few studies evaluating the comparison of the two instruments for a specific examination index [6,7], and there are no comprehensive comparative studies of the results of the two instruments. This study aimed to compare the Chord kappa, Chord alpha, corneal spherical aberration, and pupil diameter measured by the OPD-Scan III and the Pentacam, and to study the differences, correlations, and consistency to provide a reference for the selection of preoperative multifocal IOLs in cataract patients.