A deficit of the chromatic sense can also be acquired . An altered perception of colors can be found in subjects suffering from maculopathies and optic neuropathies .
More specifically, the insensitivity to a given color is related to the localization of the pathological process in progress: damage to the optic nerve compromises above all the vision of red-green colors, while the involvement of the retina tends to influence the perception of blue-yellow .
Furthermore, a slight alteration of blue-yellow sensitivity may be associated with opacity of the lens ( cataract ). Defects in discriminating the different colors can also derive from cranial trauma, from a tumor or from a stroke that has affected the visual centers.
