Color Blindness

An Ishihara Chart for testing color-blindness
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Question: Do color blind people really see only black and white?

Answer: The term "color blindness" confuses many people. The topic of color blindness is fascinating because of its complexity. Many people believe that anyone labeled as "color blind" is only able to see the colors of black and white. However, it is extremely rare to be totally color blind. Although there are exceptions, most patients affected by color blindness are able to see colors other than black and white -- they just perceive them in a different way.

Black and White Vision?

Color blind people seem to have trouble differentiating colors and may simply confuse one color with another. We all have cones in our eyes that enable us to see colors. We have red, blue, and green cones that help us to see those colors as well as combinations of those colors. In order to see all colors correctly, a person needs to have all three types of cones. 

A person who is color blind doesn't have normal cones or the cones don't work properly. If the cones fail to function correctly or make the wrong combinations, the brain doesn't receive the correct messages about the colors you are perceiving. For example, a color blind person may perceive a green leaf as gray or tan.

Is Color Blindness Hereditary?

Color blindness is often inherited, but may also occur because of eye, nerve, or brain damage, or from exposure to certain chemicals. Although it is not thought of as a  debilitating condition, color blindness can be very frustrating to a person affected by it.

Diagnosing Color Blindness

Eye doctors can test for color blindness during an eye examination. One test is a picture made up of different colored dots. The doctor will ask you to identify a picture located in the center of the dots. If a patient cannot make out a picture, he may be considered to be colorblind.

What You Should Know

Did you know that boys are far more likely to be color blind than girls? Surprisingly, about on out of every 12 boys is at least a little color blind. Boys are more affected because the gene for color blindness is located on the X-chromosome. Since males only possess one X-chromosome, they are more likely to be affected as they only need to have one defective gene. Women have 2 X-chromosomes so they would need to have the defective gene on both of them to suffer from color blindness.

Your son's diagnosis may be alarming, the sooner color blindness is detected, the better. Early diagnosis is crucial in preventing possible learning difficulties at school. Make sure to notify your son's and tell her that your son is color blindness. Adjustments can be made for him in order to help him at school.

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