Color Blindness Info: Types, Tests, Solutions

What is Color Blindness

Color blindness is the inability to differentiate certain colors. The most common form is red green color blindness however other types include blue yellow color blindness and total color blindness, and nearly all affected people are male. This relates to the fact that men only have one X chromosome (the chromosome responsible for healthy retinal development), where women have two. Through a process of natural selection, the woman’s body will choose the healthy chromosome when constructing the eye, however on very rare occasion both may be defective and the woman in question will inherit the condition. Otherwise the woman is merely a carrier – offering her male offspring a good change of being color blind.

It is interesting to note that while not proven, it is theorised that a woman with one healthy and one defective chromosome may be granted a higher perception or awareness of color than normal. The condition is however officially considered a disability and whilst it’s handicap is mostly a case of frustration, it can at times be quite dangerous.

Further Reading:

What Causes Color Blindness

Nearly all color blindness is caused by genetic inheritance of a defective X-chromosome. The defect usually comes from a carrier mother, who has a 50% chance of passing color blindness on to her son, and a 50% chance of her daughter also becoming a carrier.

Color blindness can also result from various forms of head/eye trauma induced outside the bounds of genetics. Sources can include general head trauma from accidents, Shaken baby Syndrome, Over exposure to UV rays, and more.

Within the bounds of genetics, color blindness has been found to result second hand from other hereditary diseases such as Diabetes. The list of possible sources is quite long, you can see a comprehensive list of color blindness causes here.

Common Types of Color Blindness

Color blindness comes in the following types:

  • Red Green Color Blind (most common)
    • Dichromacy (protanopia and deuteranopia)
    • Anomalous trichromacy (protanomaly and deuteranomaly)
  • Blue Yellow Color Blind
    • Dichromacy (tritanopia)
    • Anomalous trichromacy (tritanomaly)
  • Total Color Blindness (least common)

For more information, follow through to the color blindness types article.

Red green color blindness affects about 95% of all color blind people. The remaining 5% is made up of blue yellow color blindness, and less commonly – total color blindness. Within each color deficiency is the possibility of being either partially blind to that color, or totally. For example green deficient is more common, but being totally unable to see red is second most common.

Testing for Color blindness

The standard test for color blindness is known as the Ishihara Color Test. This test was created by Dr Shinobu at the University of Tokyo many years ago and has remained the  standard. The test involves a series of plates or discs comprised of hundreds of  small dots of varying shade. To a normal person the dots generally reveal a number or pattern, but to a color blind person  the pattern becomes difficult to discern.

Read on about ishihara test and other color blindness test methods here, or head straight over to the color blindness website and take their color blindness test for yourself – you just never know…

Living with Color Blindness

To the average colorblind person, the condition was a simple hurdle to overcome during childhood and ways to circumnavigate the handicap are generated naturally over time. However, color blindness is an under-publicised condition and more should be done to educate teachers and the general public on the topic. Children at school can appear to be struggling with their work when in fact they simply cant ‘pick the right pencil’ (for example).

Another serious concern revolves around when a lack of color perception creates a dangerous situation. As one example, consider a moderately severely affected red green colorblind person. Now consider how much more difficult it is for them to determine the color of the traffic lights they are driving toward.

There are also limitations of a professional nature. Color blind people can find it hard to succeed in a visual industry such as graphic design, and in select industries such as the Air Force, color blind people are simply not allowed to fill many roles on board the planes as a single mistake could prove fatal.

Most color blind people have come to terms with their handicap, and found ways to get around it during day to day living. Whether you are color blind, or you know someone who is, now is a good time to think about how you can make it easier for someone you know – helping to ease the frustration may just mean a lot to them than you think!

Color Blindness Cures & Solutions

At present there is no cure for color blindness in humans, however there are corrective lenses that can help particular individuals by using specifically shaded lenses to alter the incoming colors before they hit the retina. This can aid in determining the difference between two colors, because they are no longer in a color that the person is blind to, so to speak.

It has been theorised that gene therapy may be able to mend the genetically faulty X chromosome to cure the condition, and very recently this theory was put to test on some monkeys with very promising outcomes.

Further Reading: