Fig. 17. Diagrammatic representation of the anatomic dimensions in millimeters (mm) and degrees (°) of macular areas and of the optic disc of a right eye, left, and the corresponding circular zones in degrees (°) projected onto the right visual field. (From Gray LG, Galetta SL, Siegal T, et al: The central visual field in homonymous hemianopsia. Arch Neurol 54:312, 1997)