👁️ Curiosities
Your brain is lying to you!
Answer each question with your gut feeling – then the animation shows you the truth.
1. Which line is longer?
Same length! 😳 This is the Müller-Lyer illusion (1889). Your brain reads the arrowheads as corners in a room: lines with outward fins look like a distant room corner – and whatever seems “further away”, your brain automatically scales up.
2. Which orange circle is bigger?
They’re exactly the same size! The Ebbinghaus illusion shows that your brain never judges size in absolute terms, only relative to the surroundings. Among big circles the orange one looks small, among small ones it looks big.
3. Which square is lighter?
Exactly the same colour! With simultaneous contrast your brain judges brightness relative to the background. On a dark background grey looks lighter, on a light background darker. That’s why the same colour can look completely different in photos.
4. Are the grey lines tilted?
All the lines are perfectly straight and parallel! The café wall illusion was spotted in 1973 on the tiled wall of a café in Bristol. The offset black-and-white edges create tiny wedges in your visual system that make the lines seem to tilt.
5. The stare challenge 👁️
Press start and stare at the black dot for 20 seconds without blinking. Then the picture turns grey …
Did you see black, red and gold – the German flag? 🖤❤️💛 That’s a negative afterimage: the colour receptors (cones) in your retina get tired while you stare. On the grey surface the opposite colours briefly take over – white turns black, turquoise turns red and blue turns gold.
6. How many black dots can you see?
Zero! All the dots are white. 🤯 The scintillating grid (1994) makes black dots flash at the intersections – but only where you’re not looking. Nerve cells at the edge of your vision boost contrast and “invent” the dark spots.
