Abstract
Previous studies indicate that individuals with autism spectrum disorder (ASD) do not experience optical illusions in the same manner as individuals with typical development. This study uses pupillary responses as an objective measure of perception of visual illusions, with the hypothesis that adults with ASD will show weaker pupillary constrictions to the illusions than adults without ASD. An eye-tracker was used to investigate the spontaneous pupillary changes to brightness illusions in adults diagnosed with ASD (N = 11) and in a control group (N = 24). Contrary to the hypothesis, the ASD group showed similar pupillary constrictions to the illusory bright stimuli as the control group. Therefore, this study does not support the idea that individuals with ASD have a veridical perception of these types of illusions and instead suggest that atypical perception of illusions does not constitute a universal characteristic of aspect of high-functioning individuals with ASD.