Fig. 14. Normal disc with a sloping surface of the disc surface (which is the same as a sloping margin of the cup wall). If tissue loss begins in the lower temporal sector of a disc, as is typical of glaucoma, it may be difficult to recognize the beginning of glaucomatous damage with backward displacement of the surface of “saucerization.” It would be particularly difficult in this disc, because the tissue is a homogeneous color with few vessles by which to judge the location of the tissue surface.