Colour blindness breakdown
Accessibility • Guide • Colour blindness
@September 5, 2022
What "8% of men are colourblind” means
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Overview
"Color Blindness is not 'Color Blindness There are still a lot of people who think that if you are colorblind you really can't see any colors. But the term is misleading, as more than 99% of all colorblind people can see colors. A better wording would be color vision deficiency, which describes this visual disorder more precisely." Quote from Daniel from Colblindor from Color Blind Essentials ebook
The human eye perceives colour by a mixture of three different cones that are sensitive to specific wavelengths of light; red, green and blue.
A colour deficiency is when your sensitivity to a cone is shifted, perceiving a narrower colour spectrum.
Some statistics
Generally, colour blindness is a genetic disease affecting approximately 1 in 12 men (8%) and 1 in 200 women (0.53%) worldwide. This means:
- In Britain, there are around 3 million colour blind people; about 4.5% of the entire population
- about 300 million people worldwide, almost the same number of people as the whole population of the USA
Types of colour blindness
Dichromacy
Only two different cone types can be seen. The thrid one is missing completely
Spectrum | Denomination | Prevalence: Male | Prevalence: Female |
Red blind | Protanopia | 1.01% | 0.02% |
Green blind | Deuteranopia | 1.27% | 0.01% |
Blue blind | Tritanopia | 0.0001% |
Anomalous Trichromacy
All three cone types can be seen but with reduced sensitivity peaks in one cone. Results in seeing a smaller colour spectrum
Spectrum | Denomination | Prevalence: Male | Prevalence: Female |
Red weak | Protanomaly | 1.08% | 0.03% |
Green weak | Deuteranomaly | 4.63% | 0.36% |
Blue weak | Tritanomaly | 0.0002% |
Monochromacy
Either no conies can be seen or just one
Spectrum | Denomination | Prevalence: Male | Prevalence: Female |
Greyscale | Achromatopsia | 0.00003% |
Facts about Red-Green colour blindness
- Red-green colour blindness is a generic term used to cover several spectrums:
- red blind
- red weak
- green blind
- green weak
- More than 99% of all colour blind people experience a form of red-green colour vision deficiency.
- The deficiency severity varies, stating as slightly, through moderate effects, to string or missing a complete colour cone.
- Your whole colour vision can be affected.
More detail about colour blindness
- Coblis — Color Blindness Simulator
- Color Blind Essentials ebook by Daniel from Colblindor
Image attribution
Image by ededchechine on Freepik