A process and system for determining the topography of the bioelectric response signals of a visual system including retina, optical nerve or their projection at the level of the central cortex, following visual stimulation through a surface arranged in front of the patients eye, in which an image consisting of a plurality of cells is displayed as stimulation, each cell being activated or deactivated according to a corresponding digital time function represented by a cyclic succession of binary m-sequences of duration (T) formed from a plurality of activation symbols (N) each having a duration (Ts), the m-sequences of the various cells being obtained cyclically from a mother m-sequence, the process determining the total bioelectric response of the visual system, the response associated with each cell being determined by the total response of the visual system by means of a cross-correlation with a suitable translated version of a mother m-sequence, wherein the calculation of the response of each cell is updated at the end of each symbol time (Ts), thereby it is possible to follow the evolution of the calculated response of each cell in real time without awaiting the end of an m-sequence.
