Red-Green Color Blind Test
A focused test for red-green color blindness. It uses more contrast levels than our main test to separate protan from deutan types and estimate severity.
What number do you see?
Each plate hides a number made of colored dots. Type the number you see, or tap “I can’t see a number”.
For accurate results
- Turn screen brightness up and switch off Night Shift, True Tone, Night Light, blue-light filters and any color-adjusting apps or extensions.
- Use a phone, tablet or monitor in normal indoor light, not in direct sunlight.
- Wear your usual glasses or contacts, but not tinted or color-correcting lenses.
- Don’t zoom in or stare. Answer with your first impression within a few seconds.
Calculating your result…
Keyboard: 0–9 type the number · Enter next · Backspace delete · N or Esc can’t see a number
Before you start
- Turn your screen brightness up and switch off Night Shift, Night Light, True Tone and any blue-light or color filter.
- Use indoor light without strong colored lighting, and look at the screen straight on from normal reading distance.
- If you wear glasses for reading, wear them. Take off any tinted or color-enhancing glasses.
- Answer within a few seconds. If you can’t see a number, tap “I can’t see a number” rather than guessing.
About this red-green test
Red-green color vision deficiency affects about 1 in 12 men and 1 in 200 women of Northern European ancestry (why the difference?). This test shows plates whose number is hidden from people with missing or altered red-sensitive cones (protan) or green-sensitive cones (deutan), at four strengths from obvious to subtle. Two classification plates contain a two-digit number where each digit is hidden from a different type.
The strongest level you fail sets your severity: missing only the most subtle plates suggests a mild deficiency, missing even the strongest plates suggests protanopia or deuteranopia.
One test for all four red-green types
You don’t need a separate protanopia test, deuteranopia test or deuteranomaly test. The same plates cover all four red-green types, because each plate is built to disappear for one cone type only. Which plates you miss shows whether the red (protan) or green (deutan) cones are affected, and how many levels you miss shows whether the cones are shifted (“-anomaly”) or missing (“-opia”).
| Type | Cones affected | Approx. share of men |
|---|---|---|
| Deuteranomaly | Green (M) cones shifted | ~5% |
| Deuteranopia | Green (M) cones missing | ~1% |
| Protanomaly | Red (L) cones shifted | ~1% |
| Protanopia | Red (L) cones missing | ~1% |
Prevalence figures are approximate and for men of Northern European ancestry; they are lower in most other populations.
Reading your result
- No red-green deficiency detected: you saw the numbers at every level. Your red-green color vision looks typical on this screen.
- Mild: you missed only the subtlest plates. This usually points to a mild deuteranomaly or protanomaly. Many people with a mild deficiency never notice it day to day.
- Moderate: you missed the middle levels too. Some reds, greens, browns and oranges are probably hard to tell apart.
- Strong: you missed even the most obvious plates for one cone type. This is the pattern of protanopia or deuteranopia.
After the test, the results page shows every plate next to your answer and what typical color vision sees. Want to see what your type looks like? Open the color blind simulator or readwhat colorblind people see.
Limits of an online test
No website can control your screen’s colors, so an online test can’t diagnose color blindness. Phone and laptop displays differ, and a poorly calibrated screen can hide or reveal plates that it shouldn’t. A wrong answer on one plate can also come from a mis-tap, which is why an inconsistent pattern adds a confirmation plate at the end. If your result suggests a deficiency, an eye care professional can confirm it with clinical tests.
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
Frequently asked questions
What is red-green color blindness?
Red-green color blindness is the most common color vision deficiency. Either the red-sensitive cones (protan types) or the green-sensitive cones (deutan types) are missing or work differently, which makes some reds, greens, oranges and browns harder to tell apart.
What is the difference between protan and deutan?
Protan types affect the red-sensitive (L) cones and make reds look darker. Deutan types affect the green-sensitive (M) cones and are about three times more common. Both cause red-green confusion, but the exact colors that get confused differ.
What do “-anomaly” and “-opia” mean?
An “-anomaly” (protanomaly, deuteranomaly) means the cone type is present but shifted, so color vision is weaker. An “-opia” (protanopia, deuteranopia) means the cone type is missing, so the deficiency is strong.
Why is red-green color blindness more common in men?
The genes for the red and green cone pigments are on the X chromosome. Men have one X chromosome, so a single altered copy causes the deficiency. Women usually have a second, typical copy that compensates.
Is red or green color blindness more common?
Green (deutan) is more common. Deuteranomaly alone accounts for about 5% of men of Northern European ancestry, while protanomaly, protanopia and deuteranopia are each around 1%.
Can this test tell protanopia from deuteranopia?
It gives a likely type. Each plate is hidden from only one cone type, and the two-digit plates hide one digit from protan vision and the other from deutan vision. The difference can be hard to call on a screen, so an eye care professional should confirm the exact type.