Color Blind Test
An Ishihara-style screening for red-green color vision deficiency. Look at each plate and pick the number you see. It runs entirely in your browser.
What number do you see?
Plates are computer-generated and depend on your screen, so results are approximate. This is a screening for fun and awareness — it is not a medical diagnosis. See an optometrist for an accurate assessment.
What is the Ishihara test?
The Ishihara test, created by Dr. Shinobu Ishihara in 1917, uses pseudo-isochromatic plates — circles filled with colored dots that form a number. The figure and background share similar brightness, so they can only be told apart by hue. People with red-green color vision deficiency can't separate the colors and miss the number.
How this test works
Because the original plates are copyrighted, this tool generates its own plates in your browser each time you play. The hidden number is drawn from warm (red) dots over cool (green) dots of matched lightness, so brightness alone won't reveal it. One high-contrast plate at the start works as a control that almost everyone can read.
Accuracy and limitations
- Screen color, brightness, and lighting strongly affect what you see.
- It screens mainly for red-green deficiency, not blue-yellow (tritan) types.
- It can suggest a possible deficiency, but it cannot diagnose one.
Curious how the world looks with color vision deficiency? Try the color blindness simulator.