The effect of SOA on brightness under glare condition

LUIS ISSOLIO; ELISA COLOMBO; JOSÉ BARRAZA

Groningen, Holanda

Conferencia; ECVP 2000; 2000

Previous studies have shown the effect of brief exposures to glare on brightness, related to scotopic - mesopic range of adaptation (Colombo et al, 1999). The perceived brightness is reduced when a test patch is presented under glare condition. In this work, we measured the effect of SOA on brightness for several glare intensities. Subjects had to compare brightness of two uniform luminance fields sequentially displayed, one of which was presented under a glare condition produced by shining a bright light on the eyes. The observer reported which field was brighter with respect to another. A forced-choice paradigm with the method of constant stimuli was adopted to determine the luminance corresponding to the perceptual matching luminance. The experiment was carried out for values of SOA between 0 and 500 ms and glare intensities of 15, 30, and 60 lx measured at a point between the two pupil centres. Results show that the effect of transient glare on the matching luminance is less as SOA increases, suggesting that the time course of rapid events of adaptation affects the evaluation of brightness.