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Red-Green Color Blind Test (Free, Online)
Ten dot plates focused on red-green color vision, with a plain-words result in about 90 seconds.
This is a screening tool, not a medical diagnosis. Results depend on your screen, brightness and lighting. See an eye doctor for a proper exam. Medical disclaimer
Red-green color blind test
Last updated: . Based on the sources listed below.
How does the red-green color blind test work?
You see 10 dot plates: 2 check plates that almost everyone can read, 6 red-green plates and 2 plates that give a hint about the type. Type each number you see, or choose “I see nothing”. The plates, numbers and dot patterns are drawn by our code and are new every time. Want blue-yellow plates too? Take the full 12-plate color blind test.
Protan and deutan: what is the difference?
| Type | What the National Eye Institute says |
|---|---|
| Deuteranomaly | The most common red-green type. Certain shades of green look more red. Mild, and does not usually get in the way of normal activities. |
| Protanomaly | Certain shades of red look more green and less bright. Mild, and usually does not get in the way of normal activities. |
| Deuteranopia | Unable to tell red and green apart at all. |
| Protanopia | Unable to tell red and green apart at all. |
Our two classification plates only give a hint, and a screen cannot tell protan from deutan reliably. An eye care professional uses special tests for that. See types of color blindness for simulated examples.
What if I have trouble with the red-green plates?
First retest with full brightness and no night mode. If you still miss several plates, ask an optometrist or eye doctor for a proper color vision test. Most people with color vision deficiency do not have problems with everyday activities (National Eye Institute: Color Blindness), but it can matter for some jobs and school tasks.
Frequently asked questions
What is the difference between protan and deutan?
Both are red-green types. Protanomaly makes certain shades of red look more green and less bright, while deuteranomaly makes certain shades of green look more red. Protanopia and deuteranopia both mean no ability to tell red from green. A screen test cannot reliably tell the types apart.
What is the most common type of color blindness?
Red-green color vision deficiency is the most common kind. The National Eye Institute names deuteranomaly as the most common red-green type. It makes certain shades of green look more red, is usually mild, and does not usually get in the way of normal activities.
Why are men more likely to be color blind?
Red-green color vision deficiency is passed on through the X chromosome. Males have one X chromosome, so one affected copy is enough. Females have two, and both must carry the gene, which rarely happens, explains the National Eye Institute. Blue-yellow color blindness involves other chromosomes and affects both sexes equally.
What do I see if I have deuteranopia?
Deuteranopia makes it impossible to tell red from green at all, says the National Eye Institute. MedlinePlus Genetics describes trouble telling some shades of red, yellow and green apart. Our simulated color wheel on the types page gives an idea, but nobody sees exactly through another person’s eyes.
Do color blind glasses work?
For some people with milder red-green color blindness, special glasses may improve contrast between some colors. The American Academy of Ophthalmology says results vary, the glasses do not give natural color vision, and the effect lasts only while you wear them. They do not help if red or green cones are completely missing.
Sources
- National Eye Institute (NIH). Types of Color Vision Deficiency. Last updated August 7, 2023. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/color-blindness/types-color-vision-deficiency
- National Eye Institute (NIH). Color Blindness. Last updated November 5, 2025. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/color-blindness
- Machado GM, Oliveira MM, Fernandes LAF. A Physiologically-Based Model for Simulation of Color Vision Deficiency. IEEE Trans Vis Comput Graph. 2009;15(6):1291-1298. https://doi.org/10.1109/TVCG.2009.113
- National Eye Institute (NIH). Causes of Color Vision Deficiency. Last updated January 30, 2025. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/color-blindness/causes-color-vision-deficiency
- MedlinePlus Genetics (U.S. National Library of Medicine). Color vision deficiency. https://medlineplus.gov/genetics/condition/color-vision-deficiency/
- American Academy of Ophthalmology. Do Colorblindness Glasses Really Work? Published March 8, 2021; reviewed by Ivan R Schwab, MD and Laurie Gray Barber, MD. https://www.aao.org/eye-health/tips-prevention/do-color-blindness-correcting-glasses-work
All sources were read on October 11, 2026. We only state what the sources say, and we do not invent numbers. These pages have not been reviewed by an eye care professional. Spot a mistake? Email info@colorblindcheck.app.