Color Blindness Types & Prevalence
Color vision deficiency isn't one condition — it's a family of conditions with very different prevalence and very different effects. Here's the sourced breakdown.
Overall prevalence
Color vision deficiency affects approximately 1 in 12 men (about 8%) and 1 in 200 women (about 0.5%), or roughly 300 million people worldwide, according to Colour Blind Awareness, a UK-based charity that works directly with clinicians and researchers in the field. It's overwhelmingly hereditary, passed on an X-linked recessive pattern — which is why it's so much more common in men, who have only one X chromosome.
By type
| Type | Cone affected | Approx. prevalence in men | Approx. prevalence in women |
|---|---|---|---|
| Protanopia | Red (L-cone) | ~1.0% | ~0.02% |
| Deuteranopia | Green (M-cone) | ~1.1% | ~0.01% |
| Tritanopia | Blue (S-cone) | <0.01%, affects both sexes about equally | <0.01% |
Type-level figures vary somewhat between population studies; the numbers above are representative of commonly cited ranges rather than a single universal constant. Red-green forms (protanopia + deuteranopia, plus their milder "anomaly" counterparts) account for roughly 80% of all cases; blue-yellow (tritanopia) is rare by comparison.
What each type actually does
A common myth is that "red-green color blind" means someone sees the world in grayscale, or simply swaps red and green. In practice, most people with a red-green deficiency retain a reduced, shifted color sense across the whole spectrum — reds, greens, browns, oranges, and purples all become harder to tell apart, and even black can be confused with dark red, green, or blue. Tritanopia instead confuses blues with greens and yellows with violets/pinks.
Try the Color Blindness Simulator to see any color or photo approximated under each type.