What is Color Blindness? Ask a Raleigh Eye Doctor

When it comes to color, most of us share a common vision experience. Some people, however, have a color vision deficiency, commonly referred to as “color blindness.” Today, our Raleigh eye doctor explains the different types of color blindness, and how this interesting difference in perception occurs.

The Scientific Cause of Color Blindness

Most humans are able to see a wide array of colors. This is due to color-detecting molecules located within cone-shaped cells in our retinas, called “photopigments.” When a genetic defects causes a lack of photopigments, it results in color blindness.

The eye contains three kinds of different cones that each respond to blue, green, or red light. The type of color blindness a person experiences depends on which cones have the photopigment defect. An individual might experience red-green color blindness, the most common; blue-yellow color blindness; or total color blindness, which is rare. Below is more information on each condition.

Red-Green Color Blindness

As stated above, this is the most common type of hereditary color blindness. It is caused by either the loss or limited function of the red cone (protan) or green cone (deutran) photopigments.

  • Protanomaly: When the red cone photopigments is abnormal. Red, orange, and yellow appear greener, and colors are not as bright.
  • Protanopia: When there are no working red cone cells. Red appears black, and certain shades of orange and green appear yellow.
  • Deuteranomaly: When the green cone photopigment is abnormal. Yellow and green appear redder, and it is difficult for individuals to distinguish violet from blue.
  • Deuteranopia: When there are no working green cone cells. Reds appear brownish-yellow, and greens appear as beige.

Blue-Yellow Color Blindness

Blue-yellow color blindness occurs when blue-cone (tritan) photopigments are missing or abnormal. This type of color blindness is rarer than red-green color blindness.

  • Tritanomaly:An extremely rare condition wherein the blue cone cells are limited. Blue appears greener, and it can be difficult for individuals to tell yellow and red from pink.
  • Tritanopia:When there are no blue cone cells at all. Blue appears green, and yellow appears violet or light grey.

Complete Color Blindness

People with complete color blindness (monochromacy) don’t experience any color at all and see the world in black, white and gray. The clearness of their vision may also be affected. Complete color blindness occurs when two of the three cone cell photopigments are absent (monochromacy) or all three cone cells lack photopigments (rod monochromacy).

Raleigh Eye Center is an ophthalmology center in Raleigh, NC. If you’re looking for an experienced ophthalmologist, optometrist or optician in the Triangle area, schedule an appointment with us today.