Figure 3. A. NFD measured from the center of the nerve-head of the right eye (OD) plotted against this measurement of the left eye (OS) together with the line of equation (N = 183).

B. The distribution of differences between the NFDs measured in fellow eyes from the center of the nerve-head (N = 183). C. The difference between NFDs against NFD averaged over both eyes measured from the center of the nerve-head between fellow eyes. The solid line indicates the mean and the dotted lines the 95% limits of agreement (N = 183).