Why do we experience optical illusions and how do they trick our perception?

Our eyes can be fooled into thinking things are bigger, smaller, or even moving when they’re not, that’s called optical illusions.

Imagine you're looking at a drawing of two circles. One is on top of a black background, and the other is on a white background. Even though both circles are the same size, the one on the black background looks bigger. Why? Because our brain uses clues from around the shape to guess its size, like when you see a ball in the dark, it might look bigger because there’s nothing else to compare it to.

Your brain is like a detective that solves puzzles using hints and memories. When your eyes send messages about what they see, the brain sometimes gets confused by tricky clues, just like when you wear mismatched socks and can't tell which one is longer without looking closely.

Sometimes illusions make still pictures look like they're moving, or change color, it's all because of how your brain connects pieces of information to make sense of the world. It’s not magic, it’s just your brain having a little fun with you!