Figure 2. Full-field electroretinograms (ERGs) of a normal person and a patient with Oguchi’s disease. The rod b waves were nearly undetectable in scotopic 0.01 ERGs. The scotopic 3.0 ERGs show a significant reduction in a-wave amplitudes and a near total absence of b waves. The photopic 3.0 ERGs and photopic 3.0 flicker ERGs were almost normal.