Effects of discomfort glare on peripheral visual attention in a driving simulator

Discomfort glare is considered to have some influence on a person´s driving performance, but its effects are not well understood. It is likely that discomfort glare may irritate and distract one´s visual system during driving. In our everyday driving tasks, we must pay attention to visual information on the road to ensure driving safety, not only in the central visual field, but also in the periphery. Furthermore, with the increasing usage of head-up displays (HUDs) in modern times, we need to consider the displayed information as well, which increases the load of processing the visual information. For safety reasons, and for enhancing driving quality, this study explored possible effects of mild glare scenes on one´s peripheral visual attention. Visual stimuli presented in the central visual field and at 18° in the peripheral visual field were applied in a driving simulator in a virtual reality environment. Visual tasks were projected on a 3m by 3m projection wall at a distance of 3m to the observer. 50% of the visual tasks had a mild glare scene with a luminance of 25 cd/m² flashed before the stimulus. Results of forty-one participants showed that the mean rates of correct answers were 80.97% and 84.66% with and without applying glare respectively. We applied the theory of signal detection to analyze the experimental results. Analyzed data showed a significant difference (two-tailed t-test for dependent samples, p <; 0.001) in detectability d´ (d´_{with glare} = 1.96; d´_{without glare} = 2.36; Δd´ = 0.39). Therefore, discomfort glare causes peripheral visual attention impairment in a driving simulator in a virtual reality environment.