Fig. 6. Normal optic nerve head of moderate size with modest sized physiologic cup. Of note again is the white rim of sclera around the whole disc, seen most easily on the temporal side where the nerve fiber tissue crossing the disc margin is thinner and obscures the scleral rim less. There is a small peripapillary crescent (zone) of thin retinal pigment epithelium on the temporal side of the disc, as diagrammed in Figure 7.