What is the difference between color blind and color deficient?
The human eye can simultaneously detect three primary colors, red green and blue. All other colors are obtained by through the mixing of the three primary colors. In the case of color deficiency one or more primary colors are not detected in the normal way, while people who are color blind see shades of gray only (total color blindness). Under the most recent theory of color vision, color blindness is recognized as an extreme case of color deficiency.
