I came across this paper Color defect and color theory. The paper explained about how unilateral color blind (people who color blind only in 1 eye) actually see less bright in their color-blind eye (in graph : filled bullet) compared to the normal eye (in graph : white bullet). Especially to the scene that corresponds to the missing cone (in this paper, Deuteranopes. Missing cones = green)
I have 2 questions regarding this brightness loss in color blind people.
Green cones response are near the red cones response, and they are overlapping. How is it possible that Deuteranopes loss brightness in Green and Blue (which will make more sense if they also loss brightness in Red, thus loss brightness in the whole spectrum) but instead, still achieve the same amount of brightness in Red ? Despite Red and Green color-blind have the same color combination possibility (gamut mapping) that they can perceive ?
Could it be that color-blind people have stronger sensitivity in other cones (for example : stronger in red) and then this red opsin actually replace / fill the missing cones stimuli in retina, so their retina still able to perceive the same amount of brightness on that excessive cones ?