Color blindness is an abnormal condition, which involves the inability to clearly distinguish different colors of the spectrum. It is a misleading term because people with color blindness are not blind. Rather, they tend to see colors in a limited range; a rare few may not see colors at all. Normal color vision requires the use of specialized receptor cells called cones. (Receptor cells that allow the perception of colors.) There are three types of cones, termed red, blue, and green, which enable people to see a wide spectrum of colors. An abnormality, or deficiency, of any of the types of cones will result in abnormal color vision.
Color Blindness
noun
1.inability to distinguish one or several chromatic colors, independent of the capacity for distinguishing light and shade.
2.complete inability to distinguish colors of the spectrum, with all objects appearing as shades of gray, black, and white, varying only as to lightness and darkness; achromatopsia.