Contribution of Melanopsin to Discomfort Glare Perception

Blue light often causes discomfort glare, but it is unclear which visual pigments are the main contributing factors. Thus, we conducted an experiment to clarify the effects of two visual pigments, S-cones and melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs), by applying a silent substitution method for keeping the stimulations of L and M cones intact in foveal and peripheral vision. The color temperatures of the stimuli were 2700 K and 8000 K, and the luminance value was 1000 cd/m 2 . The background luminance was set to 5.0 cd/m 2 to create photopic conditions. Participants were exposed to the discomfort glare of the two stimuli sequentially and evaluated them using pairwise comparisons. The results showed that stimulation of ipRGCs significantly increases the discomfort glare in peripheral vision whereas the stimulation of S-cones does not, indicating that ipRGCs play a crucial role in the occurrence of discomfort glare caused by blue light.