Fig. 6. Electroretinographic responses of a normal subject and four patients with sector or stationary retinal disease. Horizontal arrows (column 1) designate range of normal rod b-wave implicit times, and vertical bar defining this range (mean ± 2 SD) has been extended through responses of patients with sector retinitis pigmentosa. Responses (middle column) from patient with Oguchi's disease are interrupted by reflex blinking, so the latter part cannot be illustrated. Cone implicit times in column 3 are designated with arrows. (Berson EL: Retinitis pigmentosa and allied retinal diseases: Electrophysiologic findings. Trans Am Acad Ophthalmol Otolaryngol 81:659, 1976)