Presence of an extensive iris defect requires implantation of artificial iris (AI) to close it. With biometric parameters of the AI being as close to an intact eye as possible, it becomes viable to achieve good clinical and functional results with the surgery. Purpose — to validate the optimal biometric parameters of the pupil of artificial iris using methods of clinical and theoretical analysis. Material and methods. Mathematical modeling was used to determine the main criteria characterizing natural aperture diaphragm of the eye (pupil) which were considered in the theoretical substantiation of optimal biometric parameters of the AI’s pupil. Parameters determined during the theoretical stage of the study were used in the development of iris-lens diaphragm (ILD) for clinical application. The study included 6 patients (6 eyes) with post-traumatic aniridia and cataract requiring reconstructive surgery. In the course of the surgery, intraocular lens and ILD were sequentially implanted into the capsular bag using injector system. The patients underwent standard and special ophthalmic examination including optical coherence tomography (OCT) of the central retina before the surgery and after 3 months. Results. According to mathematical modeling, optimal shape of the ILD pupil was determined to be a circle. The suggested diameter for the ILD pupil is 3.2 mm. The pupil must be located on the optical axis of the eye. Distortions of the retinal image become minimal with pupil’s edge thickness of 0.2 mm and cone-shaped profile. After Implantation of the developed ILD with pupil parameters determined during the theoretical substantiation, patients of the study exhibited increased visual acuity and satisfaction with results of the surgery. Conclusion. The biometric parameters of the ILD pupil determined during the clinical-theoretical study can be used in modern ILD models.