Frequently Asked Questions

Scrutinizer is a foveal vision simulator that shows designers and researchers an approximation of what users can see at a glance. It models the difference between foveal (sharp, central) and peripheral (blurry, desaturated) vision, helping you design for the scan.

Yes! The Scrutinizer Browser is completely free and open source under the MIT license. The Figma plugin is available now and has both free and premium tiers.

The Scrutinizer Browser is available for macOS (Apple Silicon). Windows can be built from source (npm run build:win). Linux is on the roadmap. The Figma plugin works everywhere Figma runs.

Scrutinizer is grounded in published visual neuroscience: cortical magnification (Schwartz 1980; Blauch, Alvarez & Konkle 2026, arXiv preprint), spatial frequency decomposition via Difference-of-Gaussians, per-channel chromatic pooling (castleCSF), and feature congestion scoring (Rosenholtz 2007). Some perceptual phenomena, such as texture synthesis for crowding (mongrels, Balas, Nakano & Rosenholtz 2009; metamers, Freeman & Simoncelli 2011), are approximated to meet real-time performance constraints. Spatial-frequency attenuation reaches a composite r = 0.60, below the r > 0.9 target (spatial acuity report). Chromatic pooling results are in the color search report. Feature congestion matches a Python port of the Rosenholtz lab toolbox at ρ=0.93. Crowding geometry is tested with reference stimuli. Wave 7c did not demonstrate the isolated-versus-flanked crowding asymmetry, and Mode 17 length-tuning and the oblique effect are not yet validated against human data. Our system paper (in preparation) details the full pipeline. See also the literature review.

The fovea is the tiny central region of your retina (about 2° of visual angle) where you have the highest concentration of cone photoreceptors. This is where you see fine detail and color. Everything outside the fovea (the periphery) has progressively lower resolution and color sensitivity.

Yes! Adjust the fovea radius with the Left/Right arrow keys or under Simulation → Foveal → Foveal Radius. You can also use our Foveal Calibrator to measure your perceptual foveal radius in pixels at your current viewing distance. The app does not import the result; set the radius by hand.

Scrutinizer Browser is built on Electron and Chromium. It captures each frame of your browsing session and processes it through a WebGL shader pipeline that applies biologically-plausible visual degradation in real-time (60fps).

Absolutely! Scrutinizer is open source (MIT license), and we encourage academic use. The shader parameters are fully documented and customizable. We have a system paper in preparation. If you publish research using Scrutinizer, please cite it once available, or reference the technical documentation in the meantime.

Scrutinizer processes every frame through a complex GPU shader pipeline. This requires continuous GPU work, which generates heat. On laptops, you may want to use an external monitor or reduce the window size for extended sessions.