Start the test
Menu

Home › Types of color blindness › Deuteranopia

Deuteranopia

People with deuteranopia have only two working cone types: red-sensitive (L) and blue-sensitive (S). Colors that differ only in how much they stimulate green cones look identical, so a whole range of reds, oranges, yellows and greens collapse into similar yellowish-brown tones.

Deuteranopia is the strongest form of deutan color blindness, also called green-blindness. The milder, more common form is deuteranomaly.

Red-green color vision deficiency · Last updated 2026-11-10

What does deuteranopia look like?

Illustration of fruit in a blue bowl with typical color vision: red apple, green apple, yellow lemon, orange, purple grapes, pink peach and blueberries.Typical color vision
The same fruit bowl simulated with deuteranopia. Red, orange, yellow and green shift toward similar olive and yellow tones, so the red and green apples look alike. Pink turns gray and purple looks blue.Simulated deuteranopia
Red, orange, yellow and green shift toward similar olive and yellow tones, so the red and green apples look alike. Pink turns gray and purple looks blue.
Nine color swatches (red, orange, yellow, green, teal, blue, purple, pink and brown) with typical vision and simulated with deuteranopia.
Common colors with typical vision (top) and simulated deuteranopia (bottom). Images are simulations based on the Machado, Oliveira & Fernandes (2009) model; real experience varies from person to person and with your screen.
  • Red, orange, yellow and green look like shades of the same yellow-brown hue.
  • Blue and yellow are still seen clearly.
  • Some pinks and purples look gray or blue.

Try our color blind simulator to see your own photos the way someone with a deutan deficiency might.

How common is deuteranopia?

About 1% of men; very rare in women.

Everyday situations that can be tricky

  • Traffic lights are usually recognized by position rather than color.
  • Color-coded information (charts, wires, map lines) often needs labels or patterns.
  • Some careers require normal color vision tests, e.g. certain pilot, rail or electrical roles.

Causes

Inherited on the X chromosome. It is lifelong and stable.

Deuteranopia vs protanopia

Both are dichromacies with only two working cone types, and both make red, orange, yellow and green hard to tell apart. The main difference is brightness: in protanopia the red-sensitive cones are missing, so reds look much darker; in deuteranopia the green-sensitive cones are missing and reds keep roughly their normal brightness. Compare the two sets of simulated images.

Read more about protanopia.

Glasses, apps and other aids

Color-enhancing glasses rarely help with deuteranopia because a whole cone type is missing; there is no red-green signal for the filter to boost. What the studies found, type by type: do color blind glasses work?

Phone and computer accessibility settings (color filters), color-identifier apps, and asking for labels or patterns on color-coded information can all help. There is currently no approved cure for inherited color blindness.

How is deuteranopia diagnosed?

Eye care professionals use plate tests (such as Ishihara or HRR plates), arrangement tests and, for a precise diagnosis, an anomaloscope. Online tests like ours can flag a likely deficiency but can’t replace a clinical test.

Take the red-green test

Deuteranopia FAQ

What colors can people with deuteranopia see?

People with deuteranopia still see color, mainly along a blue-to-yellow range. Blues and yellows stay distinct, while reds, oranges, yellows and greens fall into similar yellowish-brown tones, and some pinks and purples look gray or blue.

What does deuteranopia look like?

The images above simulate it: colors that differ only in how much they stimulate the green-sensitive cones look the same. Real experience varies, and simulations on a screen are approximations.

How common is deuteranopia?

About 1% of men; it is very rare in women. Deuteranomaly, the milder deutan type, is much more common.

Is deuteranopia the same as red-green color blindness?

Deuteranopia is one type of red-green color blindness. The red-green group also includes deuteranomaly, protanomaly and protanopia.

How do I know if I have deuteranopia or deuteranomaly?

A screening test such as our red-green test can suggest whether a deficiency is deutan or protan and how strong it is. Reliably telling a complete deficiency (deuteranopia) from a strong anomalous one needs a clinical test, usually with an anomaloscope.

Other types of color blindness

Deuteranopia is one of four types of red-green color blindness. See all types of color blindness compared side by side, or what colorblind people see with each type.

Sources

  1. National Eye Institute. Types of color vision deficiency. nei.nih.gov
  2. MedlinePlus Genetics, U.S. National Library of Medicine. Color vision deficiency. medlineplus.gov
  3. Birch J. Worldwide prevalence of red-green color deficiency. JOSA A. 2012;29(3):313–320. doi.org
  4. Nathans J, Piantanida TP, Eddy RL, Shows TB, Hogness DS. Molecular genetics of inherited variation in human color vision. Science. 1986;232(4747):203–210. pubmed.ncbi.nlm.nih.gov
  5. Simunovic MP. Colour vision deficiency. Eye. 2010;24(5):747–755. pubmed.ncbi.nlm.nih.gov
  6. Machado GM, Oliveira MM, Fernandes LAF. A physiologically-based model for simulation of color vision deficiency. IEEE TVCG. 2009;15(6):1291–1298. (Used for the simulated images.) doi.org

Note: this is a screening, not a diagnosis. Online tests can’t control your screen’s colors or brightness, so confirm any result with an eye care professional. Medical disclaimer · How the test works

More color vision tests

Color blind testFull screening: red-green and blue-yellow, with type and severity.Red-green color blind testDeeper check for protan and deutan types.Tritanopia testBlue-yellow (tritan) color vision screening.Color blind test for kidsShapes instead of numbers, for children who can’t read digits yet.Reverse color blind testHidden-figure plates that color blind people can see more easily.Color blind simulatorSee any photo the way people with color blindness see it.