Uploaded July 2013 | Updated September 2026, 3 weeks ago
This video shows how the size of the pupil changes in response to light. When a bright stimulus is presented, the pupil rapidly constricts (becomes smaller). When a dark display is presented, the pupil dilates (becomes larger). Note that constriction in response to light occurs much more rapidly than dilation in response to darkness.
This is real data (but schematically depicted, of course) from myself watching a computer display that alternates between black and white every 10 seconds. For more information, see http://www.cogsci.nl/smathot
This video shows how the size of the pupil changes in response to light. When a bright stimulus is presented, the pupil rapidly constricts (becomes smaller). When a dark display is presented, the pupil dilates (becomes larger). Note that constriction in response to light occurs much more rapidly than dilation in response to darkness.
This is real data (but schematically depicted, of course) from myself watching a computer display that alternates between black and white every 10 seconds. For more information, see http://www.cogsci.nl/smathot
