The Effect of Intermittent Preadapting Light upon Subsequent Dark Adaptation in the Human Eye*

The influence of intermittent versus continuous preadaptation upon the dark adaptation of three subjects was measured for nine brightnesses (8860 to 22.15 ml) and four rates of interruption (2 cycles/second to 1 cycle/4 seconds). The data of the subjects were combined and the mean values used in the analysis of the results. The data are so nearly alike that it is considered there is no difference in subsequent dark adaptation which is related to the mode of preadaptation—for the durations of preadaptation used. No differences are found between any curve following intermittent preadaptation and its continuous control curve nor between the different curves for the various rates of interruption.