Colorblind MCP server

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║                 your eyes, tested in the browser, with nothing leaving it                  ║
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An open, published method for color vision — and 17 vision tests built on it. Everything runs on the device. No account, no upload, no image ever sent anywhere.

The colorimetry is not a private formula: it is Machado, Oliveira & Fernandes (2009) deficiency simulation with CIEDE2000 color difference, published open access at doi.org/10.5281/zenodo.21310578, and shipped as packages so you can run the math yourself and check our numbers against yours.

Use the engine

pip install cvdsafe          # is this palette colorblind-safe?
npm  install cvdsafe

import cvdsafe
cvdsafe.is_safe(["#d7191c", "#1a9641"])   # False — red and green collapse under deutan

npx cvdsafe "#d7191c" "#1a9641"           # exits 2 if the palette is unsafe — CI-friendly

For LLM tools: cvdsafe-mcp and colorblind-mcp are MCP servers, listed in the official Model Context Protocol registry — so an assistant can check a palette or generate an Ishihara plate as a native tool.

The tests

Color vision, D-15 arrangement, hue discrimination, anomaloscope-style matching, contrast sensitivity, acuity, astigmatism, Amsler grid, blind spot, vernier alignment, flicker fusion, saturation, dominance, reaction, stereo depth, digital eye strain, and a shape-based test for kids.

A test on a web page cannot be a diagnosis: an uncalibrated display, ambient light and viewing distance all move the result. Each test says so where it reports, and points at an eye examination rather than standing in for one.

Audit it yourself. opticquiz.com/methodology answers the eight questions worth asking of any online vision test — who made it, what it measures, what it assumes about your screen, whether it has been clinically validated (it has not), what it cannot measure, and who pays for it.

Also in here

Shortened. The full README is on GitHub.