What Is Color Blindness?
People with color blindness see only about 10% of the 1- 7 million distinct colors most people with normal vision see.
Color Blindness Terms
Color Vision Deficiency (CVD) or more commonly called Color Blindness are broad terms that include a range of actual perceived vision and differing causes. The most common form of color blindness is some type of red-green color blindness. This can be genetically inherited via a recessive gene on the X-chromosome.
Retinal Color Receptors
Your retina has photoreceptors that make chemical reactions which make electrical signals that we interpret in our brain as colors. Often called the RGB or Red-Green-Blue color cones. They are more technically known as he Short (S), Medium (M), and Long (L) wavelength sensing cones.
Color Blind Types
Red-green color blindness has two types, Protan and Deutan.
Protan Color Blindness
Protans, people with Protanomaly, have a type of red-green color blindness in which the red cones are not absent but do not detect enough red and are too sensitive to greens, yellows, and oranges. As a result, greens, yellows, oranges, reds, and browns may appear similar, especially in low light. Red and black might be hard to tell apart, especially when red text is against a black background.
Someone with Protanomaly may have never seen the color purple or the color pink because seeing the red component in purple or pink is so suppressed that they view only the blue component of the color purple or the white component of pink. As a result, they often can’t tell the difference between blues and purples, or pinks and grays. People with Protanomaly usually respond positively to EnChroma glasses.
Deutan Color Blindness
Deutans, people with Deuteranomaly, have a type of red-green color blindness in which green cones are not absent but do not detect enough green and are too sensitive to yellows, oranges, and reds. As a result, greens, yellows, oranges, reds, and browns may appear similar, especially in low light. It can also be difficult to tell the difference between blues and purples, or pinks and grays. Deutans usually respond positively to EnChroma glasses.
Tritan Color Blindness
People with tritanomaly have reduced sensitivity in their blue “S” cone cells, which can cause confusion between blue versus green and red from purple. If you believe you have tritanomaly, we recommend you consult with an eye care professional for a complete vision assessment. Tritanomaly, causing reduced blue sensitivity and Tritanopia, resulting in no blue sensitivity, can be inherited or acquired.
Monochromacy and Achromatopsia
Rod-Monochromacy, S-cone Monochromacy and Achromatopsia are vision deficiencies that include partial or complete color blindness. If you have one of these conditions, we recommend consulting with a low vision specialist for a complete vision assessment.