Colour-vision simulation

At the top of Accessibility, See the page with redraws the whole page as someone with a colour-vision deficiency sees it: no red cones (protanopia), no green (deuteranopia), no blue (tritanopia) or no colour at all (achromatopsia). Use it to find where colour alone carries meaning, such as a red error next to a green success, a chart legend, or a link told apart from text only by its colour.

It uses the model of Machado, Oliveira and Fernandes (2009), the one Chrome DevTools uses, as a filter on the page. Fixed and sticky elements stay in place. Nitpique's own overlay is filtered too. The simulation turns off when you leave Accessibility or turn Nitpique off.

Strength#

While a simulation is on, a second menu sets how strong it is: Full, Strong, Medium or Mild. Most people with a colour-vision deficiency have a partial one (protanomaly rather than protanopia, for example), so Mild and Medium are closer to what many of them see. The partial strengths blend the full model with typical vision, an approximation of the published tables for each severity.

Blurred vision#

Blurred (low vision) blurs the whole page, by 3 pixels at Full and less at the milder strengths. It is a rough stand-in for reduced sharpness, not a model of any one condition: use it to see whether headings, buttons and the layout still read when fine detail does not.