Video 1: Time-lapsed video at one min intervals showing pupil constriction evoked by 480 nm light in the left eye of one of the turtles used in the study. Recording began during the last 4 min of a 30 min dark adaptation and then continued for 14 min in 480 nm light. Color of the text box at the lower left of the video codes the time and adaptation state: black for dark adaptation (0 to 4 min) and blue for 480 mn light adaptation (4 to 14 min). Note that the accompanying extraocular eye movements do not prevent pupil constriction from occurring.