[Mariotte's spot]

The blind spot with 25 healthy persons (between 19 and 64 years of age) was examined by the Octopus instrument, program 62. The established size of the blind spot for the right visual field was: 14.6 degrees +/- 0.86 up to 18.6 degrees +/- 1.5 laterally from the place of fixation and 1.4 degrees +/- 2.2 up to 4.9 degrees +/- 3.5 under the horizontal line. The depth of the defects -93.6 degrees +/- 18.9 dB for the right visual field. The established size for the left visual field was 13.2 degrees +/- 1.5 up to 16.1 degrees +/- 2.5 laterally from the place fixation and 2 degrees +/- 3 up to 4.9 degrees +/- 3 under horizontal line. The depth of defects is for the left visual filed -99.2 +/- 15.5 dB. Statistically there was no evident difference of the size and depth of the defects of the blind spot (alfa = 0.01) either between the right and the left visual field or among the individual age groups. Physicians applying computerized static perimetry should know about the spatial characterization of the individual examination programs, of the physiological size and of the possible variations of the Mariott's Point and they should evaluate the correlation of all the quantities.