People who experience visual imagination have pupillary responses that optimize the amount of light hitting the retina and change in response to imagined items. This pupillary response does not occur in those with aphantasia.
Researchers report the size of the pupil fluctuates during sleep. The findings may indicate that pupil size can indicate specific sleep states.
Personal involvement and emotional content of music influences pupillary response, researchers report.
According to a new study, how much a child's pupils dilate in response to seeing an emotional image can predict their risk of developing depression over the next two years.