Everything
you need to know.

Color vision deficiency, commonly called color blindness, is a condition where people have difficulty distinguishing certain colors. It affects about 8% of men and 0.5% of women worldwide. The most common types are red-green color blindness (protanopia and deuteranopia), followed by blue-yellow color blindness (tritanopia), and complete color blindness (achromatopsia).

Deficiency View simulates four clinically recognized types: Protanopia (red-blind) reds appear dark or black; Deuteranopia (green-blind) greens and reds blend into yellows; Tritanopia (blue-blind) blues appear greenish and yellows shift pink; and Achromatopsia (complete color blindness) all colors are perceived as grayscale.

Color vision deficiency affects approximately 300 million people worldwide. Roughly 1 in 12 men (8%) and 1 in 200 women (0.5%) have some form of CVD. Red-green color blindness (deuteranopia and protanopia) is the most prevalent.

Our simulations use the Machado, Oliveira & Fernandes (2009) color transformation matrices the same peer-reviewed methodology used in professional tools like Adobe Photoshop. All processing happens client-side in the browser.

You can upload JPG, PNG, GIF, and SVG files. For best results, use high-resolution images (at least 800px wide). The tool works with both photographs and UI mockups.

Yes. Enter any website URL and the tool will capture a screenshot and apply CVD simulations instantly. Perfect for testing existing sites, web apps, or online content.

The severity slider lets you test across the full spectrum of a CVD type from 0% (normal vision) to 100% (full deficiency). Most people with CVD have partial rather than complete deficiency.

Yes. The share feature generates a unique link that preserves your image and selected CVD type, so team members and stakeholders can instantly see the same simulation.

Deficiency View helps you identify issues covered by WCAG 2.2 Success Criterion 1.4.1 (Use of Color) and 1.4.3 (Contrast). By simulating CVD types, you can verify your designs don't rely solely on color to convey information.

Common fixes include: adding text labels or icons alongside color cues, ensuring contrast ratios meet WCAG minimums (4.5:1 for normal text, 3:1 for large text), using patterns or textures in charts, and avoiding red/green combinations.

CVD simulation covers one important dimension of visual accessibility, but a fully accessible design also needs sufficient contrast for low-vision users, scalable text, keyboard navigability, screen-reader support, and more.

Yes completely free, with no hidden costs, registration requirements, or usage limits. We believe accessibility tooling should itself be accessible to everyone.

No. Deficiency View runs entirely in your web browser. No downloads, no plugins, no account creation just visit the site and start testing immediately.

Yes. All simulation processing happens client-side in your browser. Uploaded images are never sent to our servers and are not stored anywhere. Your data stays entirely on your device.

Yes. The Deficiency View Figma plugin lets you simulate CVD, check WCAG contrast on text nodes, and export all four CVD simulations in batch directly to your Figma canvas. Search "Deficiency View" in the Figma Community.