Only about 2° of your visual field is sharp. The rest is peripheral: blurred, desaturated, crowded. Scrutinizer renders that periphery so you can design for the glance.
Designing in Figma? Try the plugin instead →
Scrutinizer models how spatial resolution, colour sensitivity, and crowding change with distance from where you're looking, approximating the falloff your retina and cortex impose.
Resolution drops with eccentricity along a log-polar mapping. Scrutinizer renders this falloff with hardware MIP-chain pooling. Each level halves spatial resolution, approximating how receptive fields grow with distance from fixation.
Colour perception narrows in the periphery: red–green sensitivity falls much faster than blue–yellow (Mullen & Kingdom 2002), and the parvocellular pathway loses resolution with eccentricity. Scrutinizer models this as selective chrominance pooling in Oklab, preserving luminance while colour bleeds and shifts.
In the periphery, objects stay visible but are hard to identify. Flankers merge with targets. Scrutinizer renders this as position jitter scaled to integration-field size, a coarse stand-in for the summary-statistic pooling of the Texture Tiling Model .
Check whether your primary CTA and key content hold up under peripheral degradation before you ship. Fixate away from the main button or heading and check whether it remains distinguishable from surrounding content.
The Restricted Focus Viewer paradigm, modernised: see where attention lands and where peripheral clutter competes with the task. The window is biologically motivated. Earlier restricted-focus tools typically used a plain Gaussian blur.
Point the open-source browser at your real app and watch it through a simulation of human perception, with live congestion scores, saliency, and peripheral falloff on the page as it ships. The browser and rendering pipeline are open source.
Eccentricity-dependent pooling, Oklab chromatic degradation, and density-gated crowding, all parameterised. The full pipeline config is embedded in each screenshot export, so a result can be reproduced.
These posts explain the models behind Scrutinizer, how they're implemented, and how the results compare with published research.
Red–green opponency collapses in the periphery; blue–yellow holds on. It has been settled vision science for 25 years and still hasn't reached the design curriculum. Road-sign design already uses it.
Read the brief →A 12-band decomposition and a biological desaturation ramp, validated against Bowers 2025 and Mullen & Kingdom 2002.
Running Rosenholtz's Feature Congestion on live pages from the app, the command line, or via MCP for AI-assisted review. Matches a Python port of the Rosenholtz lab toolbox at ρ = 0.93.
How DoG band decomposition and eccentricity-driven level selection let a graphics shortcut model peripheral acuity.
A standalone browser with the full foveated rendering pipeline. Browse any site with real-time peripheral simulation, saliency maps, congestion analysis, and mobile device emulation.
Apply foveated rendering to your Figma frames without leaving the editor. Copy static renders to canvas, or browse with live simulation.
A 30-second calibration that measures your perceptual foveal radius in pixels at your current viewing distance. The demo above uses a fixed default radius.