[Tonometry results using corneal applanation 3.53 mm in diameter]

The scale-reading of the Goldmann tonometer (1 g mass = 9.81 mN force) corresponds to an intraocular pressure of 10 mm Hg at a corneal applanation diameter of d = 3.06 mm (applanating body 1, x values) and to an intraocular pressure of 1 kPa at a corneal applanation diameter of d = 3.53 mm (applanating body 2, y values). A regression line y, calculated from 100 pairs of measurements with these two applanating bodies, with y = 0.097 + 0.1274x and a standard deviation of the y values of Syx = +/- 0.24, was within the 95% limits of tolerance at all points. Hence, the two applanating bodies are equally acceptable.