About 1 in 12 men are colorblind, which works out to roughly 8% of the male population worldwide. That’s a striking number: in a room of 50 men, four of them likely perceive color differently than the rest. Women, by comparison, are affected at a rate of about 1 in 200, or 0.5%.
Why the Gap Between Men and Women Is So Large
The genes responsible for detecting red and green light sit on the X chromosome. Men have one X chromosome and one Y, while women have two X chromosomes. If a man inherits a faulty color vision gene on his single X chromosome, there’s no backup copy to compensate. Women would need the same faulty gene on both of their X chromosomes to be affected, which is far less likely. This is why colorblindness runs so heavily through the male side of families: a woman can carry the gene without ever knowing it and pass it to a son who will experience it firsthand.
Red-Green Is by Far the Most Common Type
When people say “colorblind,” they almost always mean red-green color vision deficiency, which accounts for the vast majority of cases. Around 8% of men worldwide have some form of it. This doesn’t mean red and green look identical. More often, certain shades of red, green, orange, and brown blend together or appear muted. Some men have trouble distinguishing a ripe tomato from the leaves behind it; others struggle with traffic light colors or can’t tell when meat is fully cooked.
Blue-yellow color blindness is much rarer and isn’t linked to the X chromosome, so it affects men and women at similar rates. Total color blindness, where a person sees only in shades of gray, is extremely uncommon and affects a tiny fraction of the population.
Rates Vary by Ethnicity
The 8% figure is an average, but prevalence differs across populations. Men of European descent have the highest rates, right around 8%. Chinese and Japanese men fall between 4% and 6.5%. African American men were long cited at 4%, based on small surveys from the 1930s, but more recent studies place the figure between 6% and 7.2%.
Some of the most striking variation shows up in isolated populations. Surveys of Indigenous Australians and Papua New Guinean men found rates around 2%. In South America, nomadic tribes living at high altitudes had rates below 2%, while port communities with historical European intermarriage showed rates as high as 8%. These patterns suggest that genetic mixing between populations over centuries has gradually shifted local prevalence.
Color Vision Can Also Decline With Age
Not all color vision problems are inherited. Your ability to distinguish colors can fade over time due to cataracts, which cloud the lens and give everything a yellowish tint. Eye diseases like glaucoma and macular degeneration damage the cells that process color. Neurological conditions like Alzheimer’s and multiple sclerosis can also impair color perception by affecting the parts of the brain involved in vision. Certain medications, particularly some used for rheumatoid arthritis, list color vision changes as a side effect. These acquired forms of color vision loss can affect anyone regardless of sex.
Jobs Where Color Vision Matters
For most daily tasks, mild colorblindness is a minor inconvenience. But certain careers either require perfect color vision or become significantly harder without it. Pilots, air traffic controllers, and railway workers need to read color-coded signals accurately. Electricians and electronics technicians rely on wire color to avoid dangerous mistakes. Military roles in certain branches screen specifically for color vision.
The list extends into less obvious fields too. Pharmacists need to distinguish between similarly shaped pills of different colors. Forensic scientists interpret evidence that often depends on subtle color differences. Meat inspectors judge food safety partly by color. Careers in textiles, printing, paint mixing, and photography all rely heavily on precise color matching. Even chemistry teachers need to read color-change reactions accurately during lab work.
If you’re colorblind and considering one of these fields, it’s worth checking the specific vision requirements early. Some roles have strict screening, while others simply note that color deficiency can be a disadvantage.
How Most People Find Out
Many colorblind men don’t realize they see color differently until they’re tested, often in childhood during a routine screening. The most common test uses plates covered in colored dots with a number hidden inside. People with normal color vision read the number easily; those with a deficiency see a different number or nothing at all. Some men don’t discover their color vision is atypical until adulthood, when a specific situation exposes the gap: mismatching clothes, misreading a chart at work, or failing a vision screening for a job or driver’s license.
There’s no cure for inherited colorblindness, but most people adapt without much difficulty. Specialty glasses and contact lenses can enhance contrast between problem colors for some users, though they don’t restore normal color vision. Digital accessibility tools, like colorblind-friendly display settings on phones and computers, can also help with everyday tasks like reading graphs and maps.