Pupillary correlates of light-evoked melanopsin activity in humans.
We investigated whether cones are the only photosensitive process mediating the photopic pupillary light reflex. New analyses were performed on previously published recordings, focusing on those evoked by the onset of photopically equated short- and long-wavelength stimuli. Comparisons between responses revealed contraction differences that slowly grew to a peak and gradually declined. The late contraction was associated with short wavelengths and appeared mostly at the higher stimulus intensities. We conclude that cones are not the only photoreception process mediating the photopic ON-reflex and infer that melanopsin is another. Melanopsin contributes to the steady-state pupil size in daylight illumination.
Young
Rockefeller S L
RS
Department of Ophthalmology & Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA. rocky.young@ttuhsc.edu
Kimura
Eiji
E
D006801:Humans; D010775:Photic Stimulation / Q000379:methods; D012025:Reflex, Pupillary / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D017299:Rod Opsins / Q000378:metabolism / Q000502:physiology*; D000099210:Melanopsin
D017299:Rod Opsins; D000099210:Melanopsin