With few exceptions, FST groups correspond to ERG-based groups described by Lois et al.,14 where in both systems Group 1 has normal rod and cone (thresholds or signals), Group 2 has normal rods and dysfunctional cones, and Group 3 has dysfunctional rods and cones. Dark-adapted dim blue single flash (rod mediated) ERG amplitudes, light adapted single flash b-wave ERG amplitudes, and ERG light adapted 32-Hz flicker amplitudes are plotted by FST group. Dotted lines represent lower limit of normal ERG amplitudes.