Test du champ visuel utile

Ce que ça mesure

This test gives a rough estimate of your useful field of view (UFOV) — the speed at which you can take in visual information under divided attention. It asks you to identify a central target while also noticing where a peripheral target appeared, at briefer and briefer exposures, and reports the shortest exposure at which you can do both correctly.

Comment ça marche

On each step a central symbol and a peripheral marker flash together for a set number of screen frames, then both are instantly masked so what you saw is limited by the exposure rather than by an afterimage. You answer two questions: which central symbol you saw, and where on the surrounding ring the peripheral target appeared. Both must be correct to pass a step. The exposure starts comfortably long and steps down a fixed ladder of frame counts; the run stops at the first step you miss, and your threshold is the shortest exposure you passed. Because exposure is counted in whole display frames, the result is quantised to your screen's refresh rate.

Conseils pour un résultat fiable

• 1Don't chase the periphery with your eyes — The natural urge is to look at the peripheral marker. Resist it — relax your gaze on the cross and let the periphery come to you. This is the skill the test is actually measuring.
• 2Use a real monitor on a higher refresh rate if you can — Exposure is counted in whole frames, so a 120 Hz screen can present shorter exposures than a 60 Hz one. Comparing runs is most meaningful on the same device and refresh rate.
• 3Retest when rested — Processing speed under divided attention dips with fatigue, low light, and distraction. Trends across several runs mean more than any single threshold.