What is protonope?

Answer 1

Protonope is a type of color vision deficiency characterized by difficulty in distinguishing between red and green hues. It is caused by the absence or malfunction of the long-wavelength-sensitive photopigments in the cone cells of the retina. Individuals with protonope typically see the world in a limited color spectrum, often perceiving reds as dark or grayish, and greens as muted. This condition is a form of dichromacy, where one of the three cone types is missing.