VISUAL PERCEPTION

Müller-Lyer Illusion

You'll see two horizontal lines with arrow fins. Use the slider to adjust the bottom line until it looks the same length as the top one.

These two lines are actually identical in length — but one looks longer. That's the illusion!

INSTRUCTIONS

1.The top line is your reference — its length is fixed

2.Use the slider to adjust the bottom line so it looks the same length

3.Trust your eyes — go with what looks equal

4.After 5 rounds, we'll reveal how far off you were