ConclusionsThe location of the physiological blind spot in the visual field can be derived from fundus photographs using the formula of Bennett etal. (Graefes Arch Clin Exp 1994; 232: 361), proving it to give a close approximation of the size of retinal features. Furthermore, the conversion factor of Topcon fundus camera was close to a constant, and thus, it can be considered to function close to telecentric design.