Standard curve and physiological limits of dark adaptation by means of the Goldmann-Weekers adaptometer

Abstract

The mean (standard) curve and its superior and inferior fiducial limits at a probability of 90 per cent. for dark adaptation measured with the Goldmann-Weekers adaptometer is given. The statistical method employed is based on an arithmetical mean of the logarithms of the logarithms of the threshold (log log threshold). This curve can be used as an exact basis for the measurement of adaptation, under similar conditions of examination. That is monocular examination with a cycloplegic pre-adaptation in twilight for 15 minutes followed by light adaptation of 1,400 apostilbs for 5 minutes. Dark adaptation is tested immediately with a test object of 100 per cent. contrast eliminated by a maximum starting light of 6 lux.