If defined as diameter of image/diameter of object, the magnification M of the eye-camera system is kB, where k is a camera constant and B represents the vergence of the internal axis of the eye. The magnification may be assessed (1) from the length l of the eye, using the formula 1.336 k/(l-0.0016); (2) from the glass refraction G, using the formula kD/(1-G/D), in which D is the "normal" refractive power of the eye; or (3) from the principal point refraction A and the deviation delta D1 from the "normal" refractive power of the cornea, using the formula kD.(1 + delta B/D), where delta B = A + 0.84 delta D1. If k is 0.042 m, as in the Zeiss camera, and D is about 60 dpt, the formulas may be written as (1) M = 0.056/(l-0.0016); (2) M = 2.5/(1-0.017 G); and (3) M = 2.5.(1 + 0.017 delta B).

KRAKAU90 glaucoma cases (160 eyes) with field defects in at least one eye have been subjected to automatic perimetry on at least 5 occasions. The condition of the fields is summarized in single numbers. Regression analysis has been applied to series of such performance numbers. The trend of the development of the field defect is represented by the regression coefficient. The frequency distribution of the coefficients in groups based on references to age, sex, intraocular pressure, exfoliations, haemorrhages and therapy illustrates the possible importance or insignificance of these factors to the decay. The need for several consecutive examinations to establish with some significance a progression of field defects is demonstrated.

An instrument for automatic static perimetry at 14 points across a meridian was constructed and used in a pilot study. The machine was controlled by a computer and the subjects responded to the light stimuli by pressing one of two push-buttons. Most people investigated readily understood the rules at testing. "Blunders" made by the subject were, however, so common, that allowance had to be made in the test programme for a number of mistakes. The test stimuli should be exposed in random order. When the zone of uncertain seeing is wide - this occurs especially in untrained subjects - a simple test logic gives a fairly large variation. An improvement in reproducibility is then obtained by applying a more complicated logic, though at the cost of an increased duration of the test session.

The present material comprises 51 patients with at least one disc haemorrhage in at least one eye. A total of 127 hh were observed. The probability of finding a disc h increases with the number of examinations. The hypothesis that hh occur in all cases of glaucomatous destruction of the papillary tissue cannot be rejected, though not proven. H. seems to be connected with progression of field defects, though its effects are not immediately recognized. H. is detectable very early in the glaucomatous process; the denotation 'forerunner' is most likely justified. Hh. are highly specific for a glaucomatous process, but it has not been possible to connect h. with some clearly delimited group of glaucoma.