Color Blind Test
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Color vision

Types of Color Blindness

Color blindness is not one condition. Here is every major type — which cone is affected, how common it is, what colors get confused, and how this color blind test picks it up.

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The basics

Three cones, two ways to go wrong

Typical color vision is trichromatic: L, M, and S cones respond to long, medium, and short wavelengths, and the brain compares them. In anomalous trichromacy (names ending in “-anomaly”) all three cones work but one is shifted, so some colors look closer together than they should. In dichromacy (names ending in “-anopia”) one cone type is missing entirely, and whole families of colors collapse into one.

Red-green color blindness

By far the most common family. The genes for the L and M cone pigments sit on the X chromosome, which is why red-green color blindness is so much more common in men. “Protan” types involve the L (red) cone; “deutan” types involve the M (green) cone.

Deuteranomaly

M (green) cone shifted toward red

How common
About 5% of men, 0.35% of women — the most common type
What it looks like
Greens look duller and closer to reds and oranges; yellow-greens, beiges, and browns blur together. Severity ranges from barely noticeable to near-deuteranopia.
In this test
Lowered green (M cone) score with a red score that stays higher.

Protanomaly

L (red) cone shifted toward green

How common
About 1% of men
What it looks like
Reds look weaker and darker, and red, orange, yellow, and green are harder to separate. Red traffic and brake lights can look dim.
In this test
Lowered red (L cone) score with a green score that stays higher.

Deuteranopia

M (green) cone missing

How common
About 1% of men
What it looks like
Two-color vision along a blue–yellow axis. Reds, greens, and oranges collapse into similar mustard and olive tones.
In this test
Green score in the strong band — even the easiest green-axis plates read as blank.

Protanopia

L (red) cone missing

How common
About 1% of men
What it looks like
Like deuteranopia, plus deep reds look very dark or almost black because the long-wavelength end of the spectrum is lost.
In this test
Red score in the strong band.

Blue-yellow color blindness

Tritan types involve the S (blue) cone. The inherited form is carried on chromosome 7, so it affects men and women equally — and it is rare. Blue-yellow loss is more often acquired, from aging of the lens, glaucoma, diabetes, or some medications.

Tritanomaly

S (blue) cone weakened

How common
Rare — roughly 1 in 10,000 people, equally in men and women
What it looks like
Blue and green, and yellow and pink or violet, become hard to tell apart. Often acquired with age, cataracts, or eye disease rather than inherited.
In this test
Lowered blue (S cone) score while red and green stay typical.

Tritanopia

S (blue) cone missing

How common
Very rare — under 1 in 10,000
What it looks like
The world shifts toward reds, pinks, and teals; blue looks greenish and yellow looks pale pink or light grey.
In this test
Blue score in the strong band.

Complete color blindness

Total or near-total color blindness is very rare and usually comes with other vision symptoms. It is typically diagnosed in childhood rather than discovered with a screening test.

Monochromacy (achromatopsia)

One or no working cone types

How common
About 1 in 30,000
What it looks like
Little or no color — the world appears in shades of grey — usually with light sensitivity and reduced sharpness.
In this test
All three scores very low, while the warm-up plate (which uses brightness) is still readable.

Find out which type you have

The test on the home page scores your red, green, and blue cones separately, so it can point to a protan, deutan, or tritan pattern and estimate how strong it is. Read how the test works first if you want to understand the scores.

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