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Detect Color Blindness

Color Blindness Simulator

Ever wondered what colour blind people see? Load an image or use your camera and compare normal vision with protan, deutan, tritan and monochromatic vision, side by side.

Normal vision
Protanopia (simulated)

Upload a photo, use your camera, or load a sample to see the difference.

Private by design. Images and camera frames are processed entirely in your browser and are never uploaded. The simulation is a research-based approximation, not an exact reproduction of anyone's vision.

What do color blind people see?

There's no single answer, because colour blindness comes in types and strengths. Someone with deuteranopia sees reds, greens and browns collapse toward beige; someone with tritanopia loses the blue-yellow distinction instead. This tool applies scientifically-derived transforms to approximate each case.

How the simulation works

Each pixel's colour is passed through a matrix that models how a given deficiency mixes the red, green and blue channels. It's a close, research-based approximation, real perception varies from person to person and can't be captured exactly on a screen, but it's very effective for understanding, designing accessible materials, and empathy.

Designing for colour blindness

Use it to check whether your charts, maps, slides or UI still work without colour: if two categories look identical in deuteranopia, add labels, patterns or shape cues. That's exactly why this whole site avoids red/green-only signals. Curious about animals? See how dogs see colour and how cats see colour.

Then test your own colour vision to see which simulation is closest to how you see.

Frequently asked questions

How does the color blindness simulator work?
It applies scientifically-derived colour-vision-deficiency transforms to each pixel of your image, so you can see an approximation of how a scene looks with protan, deutan, tritan or monochromatic vision. Everything is processed in your browser.
Are my photos uploaded anywhere?
No. Images and camera frames are processed locally on your device and never sent to a server.
Is the simulation exactly what a color blind person sees?
It's a close, research-based approximation, not a perfect reproduction, real colour perception varies from person to person and can't be captured exactly on a screen.