DETERMINATION OF THE MEASUREMENT METHOD OF CFF AS A REFLECTION OF VISUAL FATIGUE.

Abstract

CFF varies in magnitude and variance, depending on measurement methods and stimulus conditions. In the present experiment, we examined the effects of four measurement methods, i. e. a method of adjustment, a modified method of adjustment, a method of limits and a constant method, and the three stimulus variables of luminance (120 cd/m**2 and 530 cd/m**2), size (1 degree and 2. 5 degree ) and IED-color (green, yellow and red) on the variation of CFF caused by visual fatigue. The results show that (1) the method of limits gave the smallest variance; (2) the test stimulus of 530 cd/m**2 produced a greater reduction in CFF than that of 120 cd/m**2; (3) the test stimulus of 1 degree produced a smaller variance than that of 2. 5 degree ; (4) there was no significant difference in magnitude and variance among the three colors of green, yellow and red.