Blue color blindness. Blue color blindness, which is rare, is an inability to distinguish both blue and yellow. Blue and yellow are seen as white or grey. Although as many females as males have this deficiency, it usually appears in people who have physical disorders, such as liver disease or diabetes mellitus. However, it is not uncommon for young boys to have blue/green confusion that becomes less pronounced in adulthood.
alsoBlue color blindness, also known as incomplete achromatopsia or blue-cone monochromatism, is an X-linked recessive disorder in which only the blue cones and the rods are functioning properly. A previously proposed theory states that signals from rods travel in the same pathways which carry signals from the blue-cones, making color vision in a blue-cone monochromat impossible. However, current research on blue-cone monochromats shows that signals from some rods and cones may be traveling by separate pathways to where wavelength discrimination takes place, making color vision possible in this type of monochromat, when both rods and blue cones are working simultaneously under twilight conditions.
Lewis often mixes up blues and greens.
