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Detect Color Blindness

Types of Color Blindness

By The Detect Color Blindness editorial team Last reviewed

"Colour blindness" is rarely total. Most people with it see colour, just a narrower range, because one type of cone in the retina is missing or shifted. Which cone is affected, and how strongly, defines the type.

By type

Deuteranomaly Red-Green

Reduced sensitivity to green light, the most common form.

~5% of men (about 1 in 20) Read more →
Deuteranopia Red-Green

Absent green cones, a stronger red-green deficiency.

~1% of men Read more →
Protanomaly Red-Green

Reduced sensitivity to red light; reds look dimmer.

~1% of men Read more →
Protanopia Red-Green

Absent red cones; a strong red-green deficiency.

~1% of men Read more →
Tritanomaly Blue-Yellow

Reduced sensitivity to blue light; rare.

Very rare (affects men and women equally) Read more →
Tritanopia Blue-Yellow

Absent blue cones; blue-yellow confusion. Rare.

Very rare (< 0.01%) Read more →
Achromatopsia (Monochromacy) Total

Little or no colour vision, seeing mostly in shades.

Extremely rare (~1 in 30,000) Read more →

Guides

Understand color blindness

What Causes Color Blindness? The genetic and acquired causes of color blindness, from inherited cone changes to disease, medication and aging. Read → The Genetics of Color Blindness How color vision deficiency is inherited on the X chromosome, and why it is far more common in men than women. Read → How Common Is Color Blindness? Color blindness prevalence by type, sex and ethnicity, roughly 1 in 12 men and 1 in 200 women. Read → Color Blindness Facts Clear, sourced facts about color blindness: what it is, who has it, myths, and what daily life is actually like. Read → Can Women Be Color Blind? Yes, women can be color blind. Why it is rarer, how the X-linked inheritance works, and the carrier question. Read →

The three colour axes

Human colour vision uses three cone types, long (red), medium (green) and short (blue) wavelength. A deficiency in any one shifts how you separate colours:

  • Red-green (protan and deutan), the L or M cones. By far the most common, and X-linked, so it mainly affects men.
  • Blue-yellow (tritan), the S cones. Rare, and affects men and women equally.
  • Total colour blindness (monochromacy), little or no cone-based colour at all. Extremely rare.

Not sure which applies to you? The quickest answer is to take the color blind test, it estimates your axis and strength in about a minute.

Keep exploring

What next?

Take the color blind test 14 quick plates · instant type & severity · no sign-up. Start the test → See how you see colour Simulate protan, deutan, tritan & more on any image. Open the simulator → Do colour blind glasses work? Honest comparison of EnChroma, Pilestone & ColorLite. Read the guide →