What Causes Colorblindness?

Dr. Jim Martin 09/05/2014

close-up-eye.jpgApproximately 250 million people around the world, with a concentration of nearly five percent of the population in the United Kingdom, are colorblind.

Color is interpreted by a combination of specialized cells in the eyes known as cones and rods. The cones are located on the retina, the central location for a person to process images. When a person has a defect with these cells, or the pathways between the cells and brain, it can result in faulty interpretations of the colors within an image.

There are three types of cone cells that combine their information to bring about the vivid colors that individuals see. The primary colors are red, green and blue. Depending upon the level of severity, a person can suffer with a mild to complete loss of color.

Types Of Color Vision

Normal color vision is called trichromacy. These individuals have all three cones working together to produce accurate images. This color deficient condition occurs when all three cones are still functioning, but one of the cone types is not fully interpreting the color specific to their cell, creating a skewed color image.
  • Protanomaly is a condition in which the cones responsible for processing shades and tints of red do not function normally.
  • Those with deuteranomaly have a defect in the cones that translate green in images.
  • Tritanomaly affects the cone cells responsible for bringing shades of blue to vision.

Dichromacy is a defect in color vision that is the result of one of the the three cone cell types being nonfunctional. With only two of the three cones working properly, people will have a lack of the colors associated with the cone that is not working.

Monochromacy, or achromatopsia, is a total lack of color as a result of all three cones being faulty.

How Does Colorblindness Occur

The X chromosome carries the genetic code that often leads to red/green color deficiencies. It is passed down from the mother who may be a carrier, but not suffer from the condition herself. This is also the reason more men than women have issues with colorblindness.

If you have questions or concerns regarding colorblindness, the professionals at Broome Optical are ready to guide you through the effects of this condition.

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