A full-field system is described for recording the human electroretinogram (ERG). The full-field stimulus and background minimize the problem of stimulation of large areas of the retina by stray light. Normal responses are illustrated under stabilized conditions of adaptation to single flashes of white light, as well as short wavelength and long wavelength light stimuli matched in brightness for the cone and rod systems, respectively. In this system, measurement of the temporal aspects of the ERG not only helps to establish diagnoses, but also provides information about visual prognosis in patients with hereditary retinal disease.