Measure the Trick
Drag until it looks right. Then find out how wrong it was.
The standout experiment
Play
Six classic size illusions, one slider each. Drag until the orange shape looks exactly the same size as the dark one, lock it in, and we measure how far out your eyes were. Then the trick gets switched off so you can see the truth.
The drawings and the scoring are ours; the explanations come from Michael Bach’s Optical Illusions & Visual Phenomena and Britannica, linked on every reveal.