Objective. In this study, we propose a new method for evaluating the functional results based on the sizes of phosphenes that the patient drew which were then digitalized. We also describe the methodology of psychological testing and support for a deaf-blind patient. Approach. A 59-year-old man with retinitis pigmentosa and hearing loss (clinical Usher syndrome) underwent surgery to implant the Argus II retinal prosthesis system in his right eye. Main results. Correlation analysis showed a weak dependency between the size of a phosphene and the perceptual threshold. Significant correlations between a phosphene and the height of the interface, impedance or retinal thickness was not found. The patient with the retinal prosthesis felt more independent and confident, and more healthy. This is the first case of retinal implant surgery in Russia. Significance. The results of this study add to the understanding in the field of retinal implants functioning. The experience of the successful rehabilitation of the deaf-blind patient after implantation of Argus II allowed us to design a methodology that can be used in future similar cases.