Blue-light effects on saccadic eye movements and attentional disengagement

Abstract

People are constantly exposed to high-energy blue light as they spend considerable amounts of time reading and browsing materials on electronic products like computers and cellphones. Recent studies suggest that the stimulation of intrinsically photosensitive retinal ganglion cells (ipRGCs)—a newly discovered type of photoreceptor shown to be particularly sensitive to blue light—activates brain regions related to eye movements and attentional orienting (e.g., frontal eye fields). It remains unclear, however, whether and how blue light affects eye movements and attention behaviorally. We examined this by adopting the gap paradigm in which participants made saccades to a peripheral target as quickly and accurately as possible while the fixation sign vanished (i.e., the gap condition) or remained visible. Participants were exposed to blue and orange light on two separate days. Faster saccade latency under blue light was found across two experiments, and the results indicate that blue light shortened saccade latency when attention and eye movements operate simultaneously. Our findings provide evidence for the blue-light facilitatory effect on eye movements and attentional disengagement, and suggest that blue light can enhance the speed of saccadic eye movements.