A loss of color perception in the red area of the spectrum of visible light. In this condition there is difficulty distinguishing red and green as separate colors and could be attributed to a deficiency of specific photo pigments in retinal cones.

PROTANOPIA: "Protanopia can be a reason to memorized the color sequence on stop lights."
Cite this page: N., Pam M.S., "PROTANOPIA," in, April 28, 2013, (accessed September 28, 2021).