The optical illusion appears to show two grey squares with different shades, but they are actually exactly the same colour.

Optical illusion challenge: Optical illusions have become a viral trend on social media, and it's easy to see why! These clever brain teasers aren't just entertaining to look at; they also test your ...

An optical illusion is a visual phenomenon in which our perception of an image differs from objective reality. This image is ...

Challenge your brain with a cosmic optical illusion that hides a mythical figure in plain sight. Can you solve it fast?

This optical illusion challenges readers to spot a hidden umbrella among numerous ostriches within 11 seconds.