Binocular Summation in Postillumination Pupil Response Driven by Melanopsin-Containing Retinal Ganglion Cells

Bright blue light stimulation induced a greater postillumination pupillary response under binocular than monocular viewing conditions.

• Pupillary responses were measured in 10 visually normal participants using chromatic pupillometry.
• Under binocular conditions, the postillumination pupillary response (PIPR) was significantly larger in response to bright blue light compared to monocular conditions.
• Bright red light stimulation resulted in minimal PIPR, with no significant difference between monocular and binocular viewing conditions.
• Maximum pupillary constriction (MPC) was greater during binocular viewing for all light stimuli, with the highest MPC observed following blue light stimulation.
• The findings suggest that signals from intrinsically photosensitive retinal ganglion cells are combined when both eyes are used.

AI simplified