Color Blindness Test

Read the number hidden in each dot plate to screen for red-green color vision deficiency — the most common type. Self-generated plates, scored instantly, all in your browser.

How the test works

Each circle is a pseudo-isochromatic plate: a number drawn in one set of colours, sitting in a field of dots in another set. The two sets differ mainly along the red-green axis but are matched in brightness, so you can't use lightness to cheat — only hue. Typical colour vision separates the hues and the number pops out; red-green deficiency blends them together, so the number is faint or invisible. The first plate is a demo almost everyone can read, to confirm your screen is showing the colours properly.

Screening, not a diagnosis. These plates are generated by the tool (not the official Ishihara set), and your monitor, brightness, blue-light filter and night mode all shift colours. Use it for awareness or a quick check — then see an eye-care professional for a real diagnosis. Nothing is uploaded; it runs in your browser.

About red-green color blindness

Colour vision deficiency affects roughly 1 in 12 men and 1 in 200 women. The most common forms — protan and deutan — make reds, greens, oranges and browns easy to confuse. It's usually inherited and lifelong, and most people with it see colour perfectly well most of the time; specific pairs are just hard to tell apart. Less common is tritan (blue-yellow) deficiency, which these red-green plates don't target.

Get the most reliable result

Turn screen brightness up, switch off night mode / blue-light filters, view in a neutrally-lit room, and sit at a normal distance. If you read the demo plate but miss several others, that's the pattern worth following up professionally.

Frequently asked questions

How does a color blindness test work?

You read a number hidden in coloured dots. The number and background differ in hue but match in brightness, so red-green deficiency can't separate them and the number disappears.

Is this an official Ishihara test?

No — the plates are generated here, and your screen affects colours. It's a screening and awareness tool, not a clinical diagnosis.

What is red-green color blindness?

The most common colour vision deficiency: reds, greens, oranges and browns are easy to confuse. Usually inherited and far more common in men.

How do I get an accurate diagnosis?

See an optometrist or ophthalmologist; they use calibrated plates and tests like the anomaloscope or Farnsworth D-15.

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