Abstract: A system and method for obtaining information about the spatial distribution of photoreceptor activity and neural activity in the retina using simultaneously recorded multiple biopotential signals. The information thus gathered is used to assess retinal dysfunction due to trauma or disease. The biopotential signals are recorded from the surface of the eye and head using a plurality of electrodes, including those integral to a contact lens. The biopotential signals are recorded before, during and after the presentation of an optical stimulus to the subject eye. The recorded biopotential signals are then analyzed and interpreted to reveal the distribution of photoreceptor activity and neural activity across the retina. The analysis and interpretation of the biopotential signals is quantitative, and makes use of an electromagnetic model of the subject eye. The subject may be animal or human.