Color Vision
Everyone sees colors differently. In extreme cases, it is possible that one or more colors are not recognized but are seen as shades of gray (color blindness). A color deficiency is present if certain colors are perceived in modified form or in a different saturation. Under these circumstances, one or more of the three types of receptors in the eye does not work properly, it at all. In the case of red or green blindness, the corresponding receptors do not provide any color information. For example, only differences in brightness are perceived, not the colors. These color vision defects are always congenital and are incurable. Sufferers merely acquire higher sensitivity for different degrees of brightness.
