Skip to main content
Playground

Mueller-Lyer Illusion

Perceptual length illusion bias

This is a solo practice run: your results stay in this browser tab and are never sent anywhere. To contribute to a class result, join a live session with a code instead.

Instructions

Mueller-Lyer Illusion

You will see two horizontal lines with different arrowhead patterns.

Your task is to decide which central line looks longer, even when they are physically similar.

Response Keys
[F] Left Longer
[J] Right Longer

Starts with a short practice round that is not scored.

Total trials: 20

Example
All tasks