About Trust Your Eyes?

Trust Your Eyes? is a small perception lab. It shows six classic visual illusions, each redrawn from scratch for this page: two lines with arrow-shaped ends, circles surrounded by bigger and smaller circles, two bars between converging lines, grey squares on dark and light backgrounds, a wall of offset tiles, and straight lines over a fan of rays. Most of them were first described by psychologists more than a hundred years ago, and they still work on almost everyone.

What you do here

For each illusion you answer a simple question first, such as which line is longer or whether two lines are straight. Then you switch on "Remove the context". That hides or neutralises the part of the picture that misleads you and adds plain guide lines, so you can check the answer with your own eyes instead of taking our word for it. A short note explains what the illusion is usually taken to show. At the end you see how many fooled you.

What the explanations say, and what they do not

The notes stick to what is well established: the measured lengths, sizes and shades on this page really are equal or straight, and in each case the surroundings change how we see them. Why our visual system does this is a different matter. Some explanations, such as the idea that the arrow-shaped ends work like depth cues, are long-standing but still debated by researchers, and the notes say so rather than presenting one theory as settled. Being fooled is not a flaw in your eyesight: these effects show how vision normally uses context to make sense of the world.

Where the AI comes in

At the end you can ask for a short lab note about your results. It is written live by AI, labelled as AI, and instructed to make only general statements about perception, with no statistics or claims about specific studies. If the AI service is busy, the page shows a hand-written note instead and says so. For real research, follow the sources in our articles.

Your results

Nothing is stored or sent, except the list of illusions that fooled you when you ask for the AI lab note. Screens differ, so if a drawing looks squeezed on yours, the guide lines in "Remove the context" are the fair test.

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