Color correction for your whole screen.
DOA's other half. Color adjustment modes for Protanopia, Deuteranopia, and Tritanopia, applied across every app on your Windows desktop. No prescription, no calibration, no setup. Turn it on and it works.
See it before you download
This dashboard is the kind of screen that breaks with color vision deficiency: a red line and a green line, a pass and a fail, a row of category colors. Pick a vision type to see what happens to it, then switch the correction on.
Normal vision. This is the reference: five clearly distinct category colors, and a red line you can tell apart from a green one. Pick a vision type above to see how much of that survives.
This is a showcase, not the product. What you see here is one fixed setting applied to one sample image in a browser. The correction inside DOA is stronger and adjustable: you choose your deficiency type, tune the intensity to your own vision rather than a textbook average, and it runs live across everything on your screen instead of a single picture. Treat this as a rough preview of the idea, not a measure of how well it will work for you.
The simulation runs in your browser using published color vision matrices (Machado, Oliveira & Fernandes, 2009), and the correction uses the same daltonization approach DOA builds on. Real color vision deficiency varies from person to person; these settings show the strongest form of each type, so treat this as an illustration rather than a measurement of your own vision. More in the FAQ.
Why a screen-wide filter, and not per-app settings
Some apps ship a colorblind mode. Most don't. That leaves you toggling settings in the few places that offer them and squinting everywhere else, and it does nothing for a website, a spreadsheet, a video, or a game that never considered it.
DOA works at the display level, so the adjustment applies to everything on screen at once: every app, every browser tab, every document. You set it once and stop thinking about it. Windows has its own built-in color filters, and they're a reasonable starting point, but they apply a single fixed transform. DOA's modes are built per deficiency type and sit alongside the rest of what the app does.
The three types DOA covers
Color vision deficiency affects roughly 1 in 12 men and 1 in 200 women. It runs along two different confusion axes, which is why one filter can't cover everything.
Protanopia
Reds look much darker than they are, sometimes close to black, and blur into dark greens and browns. DOA amplifies the red channel so those tones register.
Deuteranopia
Greens shift toward brown and orange until they're hard to separate from reds. The red-green family is by far the most common. DOA rebalances the green channel so the two pull apart.
Tritanopia
A different axis entirely: blues drift toward green and yellows toward pink or white, so red and green stay readable while blue and yellow stop working. The rarest type. DOA remaps that axis instead.
A note on naming: the -anopia names above mean a cone type is missing altogether. The milder and more common versions, where a cone is present but shifted, are called protanomaly, deuteranomaly, and tritanomaly. The simulator shows the full -anopia forms, so what you see there is the strongest case rather than the typical one.
What this is, and what it isn't
Straight answers before you download
- It does not cure or change your color vision. It changes what your screen sends, so colors that used to collapse together arrive separated. Away from your screen, nothing is different.
- The simulator above is not a test. It shows what the strongest form of each type does to a sample image. It cannot tell you whether you have a color vision deficiency, and screen calibration varies too much for any web page to do that reliably. An optometrist can.
- The simulator is also not the product. It runs one fixed correction on one image to demonstrate the idea. The app applies a stronger correction that you tune to your own vision, in real time, across your whole screen. Expect the real thing to do more than the preview.
- Correction is a trade. Pulling confusable colors apart shifts other colors slightly in the process. It's the right trade when you need to read information, and the wrong one for color-critical design or photo work, so turn it off for those.
- It's free. Color filters are included in the free tier, no prescription and no card needed. The free tier's limits are a daily usage cap and a small logo in the corner.
Turn it on and see for yourself
Free on Windows 10 and 11. No prescription, no card, about a minute to set up.