Color blindness is a common eye condition that affects males more than females. The term color blindness is applied to anyone who has abnormal color perception and does not indicate a true lack of color perception, only one that is altered from the normal. Most color-blind individuals are red-green color blind, but it is also possible to have blue-yellow color defects. Color blindness has no impact on the best possible eyesight or function of the eyes. The biggest impacts of color blindness are lifestyle and career choices.
What Determines Color Vision?
Color vision comes from retinal cells called cone photoreceptors. There are three different types of cone photoreceptors in typical, healthy eyes.
There are red, green, and blue cones or long wavelength, medium wavelength, and short wavelength cones.
These cones each respond to light differently based on what wavelength or color of light is produced or reflected.
By combining the responses from all three types of cone cells, normal color vision is produced.
What Happens in a Color Blind Individual?
In color blindness, one or more of the cone cells are abnormal or absent. Typically, the red or green cones will be either missing altogether or occur in a much lower than the normal amount.
This difference in the number of cone photoreceptors affects the perception of colors by the retina and thus the color perception of the individual.
When either the red or the green cone is missing, the entire red end of the spectrum will appear as one color with different shades.
If either of the red or green cones is abnormal, there will be more differentiation of the red and green spectrum but it will be less than in a normal individual.
Inheritance of Color Blindness
Red-green color blindness is usually an X-linked inherited condition. This means that it is inherited alongside the X gene which is a sex chromosome.
Males only have one X gene while females have two X genes. Since males only have one X chromosome, it is much more likely that they develop color blindness.
If a female has one affected and one unaffected X chromosome, the unaffected will dominate and there will be no color blindness.
However, if a male inherits an affected X chromosome, he will develop color blindness.
For this reason, it is common to see color blindness run in maternal family lines with only the males being affected.
Effects of Color Blindness on Lifestyle
Color blindness is not a debilitating condition and does not affect the best possible eyesight at all.
In fact, most color-blind individuals have no clue that they are the ones who are perceiving things differently and only realize after a comparison test that there is a difference.
The biggest impacts of color blindness on affected individuals are small lifestyle modifications and career choice considerations.
Knowing that their perception of colors may differ from the normal, those with color blindness may ask for assistance with matching clothing, decorating, or other tasks in which color coordination is needed.
There are a few careers that require color vision and are unable to be achieved by a color-blind individual including a pilot, some types of train engineers, and in some cases electricians.