How Common Is Color Blindness?
The reason men are affected so much more often comes down to genetics. The genes responsible for the most common types of color blindness sit on the X chromosome. Men have one X chromosome — if it carries the variant, they're affected. Women have two X chromosomes, so the second copy usually compensates.
Not sure if you have color vision differences? Take the test — it checks for the most common types in about 2 minutes.
Take the Color Blind Test →The 4 Main Types
This is an umbrella term for four related subtypes, all involving difficulty distinguishing red and green wavelengths. It's by far the most common form of color vision deficiency.
Deuteranomaly — the most common subtype overall. Reduced sensitivity to green light. Greens appear more red. Affects about 5% of men.
Deuteranopia — complete absence of green cone function. Red and green are indistinguishable. Affects about 1% of men.
Protanomaly — reduced sensitivity to red light. Reds appear darker and less saturated. Affects about 1% of men.
Protanopia — complete absence of red cone function. Red appears very dark, almost black in some cases. Affects about 1% of men.
Blue-yellow color blindness is much rarer than red-green and affects men and women equally — it's not X-linked. People with this type have difficulty distinguishing blue from green, and yellow from violet or red.
Tritanomaly — reduced blue cone sensitivity. Blues appear greener, yellows appear more pink. Very rare.
Tritanopia — complete absence of blue cone function. Blues and greens are confused, and yellows and pinks appear similar. Extremely rare.
Unlike red-green color blindness, tritanopia can sometimes be acquired — caused by aging, certain medications, or eye diseases — rather than inherited.
Complete color blindness means seeing only in shades of grey — no color information at all. This is genuinely rare and is usually accompanied by other vision issues including extreme light sensitivity (photophobia), reduced visual acuity, and involuntary eye movements (nystagmus).
Most people who describe themselves as "completely color blind" actually have a form of red-green color blindness — the total absence of color perception is much rarer than the name suggests.
Some people have normal color vision in one eye and color blindness in the other. This is called unilateral color blindness and is almost always acquired rather than inherited — usually from eye injury, disease, or neurological damage rather than genetics.
Because the unaffected eye compensates in everyday life, many people with unilateral color blindness don't know they have it until tested.
What Color Blindness Actually Looks Like
A common misconception is that color blind people see the world in black and white. For the vast majority, that's not true. The experience depends on the type:
- Red-green color blindness: reds, greens, browns, and oranges all look similar — a muddy range of yellow-brown tones. Traffic lights are distinguishable by position, not color.
- Blue-yellow color blindness: blues and greens merge, and yellows can look pink or red.
- Achromatopsia: genuinely monochromatic — only brightness differences, no color at all.
Most color blind people adapt well and find workarounds for everyday situations. The main challenges come in specific contexts: reading color-coded charts, picking out ripe fruit, or distinguishing certain safety signals.
How to Find Out What Type You Have
An online color blind test — like the Ishihara plate test — can identify whether you have color vision differences and suggest the likely type. It's not a clinical diagnosis, but it's a reliable indicator for the most common forms.
For a confirmed subtype diagnosis, an optometrist can perform a comprehensive color vision test using tools like the Farnsworth-Munsell 100 Hue Test, which maps exactly which wavelengths you have difficulty with.
Find out if you have color vision differences — the test takes about 2 minutes and shows your results instantly.
Take the Color Blind Test →Frequently Asked Questions
What are the types of color blindness?
The main types are red-green color blindness (the most common), blue-yellow color blindness (tritanopia), and complete color blindness (achromatopsia). Red-green is further divided into deuteranopia, protanopia, deuteranomaly, and protanomaly.
What is the most common type of color blindness?
Red-green color blindness is the most common, affecting about 8% of men and 0.5% of women. Deuteranomaly — reduced sensitivity to green — is the single most common subtype.
Can color blindness be cured?
There is currently no cure for inherited color blindness. Tinted lenses can enhance color contrast for some people but don't restore normal color vision. Gene therapy research is ongoing.
How do I know what type of color blindness I have?
An online color blind test can indicate whether you have color vision differences and suggest the likely type. For a confirmed diagnosis, an optometrist can perform a comprehensive color vision assessment.
Is color blindness more common in men or women?
Much more common in men — about 8% of men vs 0.5% of women. This is because the most common forms are inherited on the X chromosome, and men only have one X chromosome.