a photosensitive pigment found in retinal cones in the eye which have a sensitivity to wavelengths of light which do not exceed a frequency of 558nm.

LONG-WAVELENGTH PIGMENT: "A long-wavelength pigment is a photosensitive compound, found in the retina, which is sensitive to long wavelengths of light only."
Cite this page: N., Pam M.S., "LONG-WAVELENGTH PIGMENT," in PsychologyDictionary.org, April 7, 2013, https://psychologydictionary.org/long-wavelength-pigment/ (accessed September 23, 2021).