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

Our brains sometimes get confused by what our eyes see, and that’s why we experience optical illusions.

Imagine you're looking at a drawing of two lines, one straight, the other bent. But because of how they’re surrounded by other shapes or colors, your brain thinks the straight line is actually slanted. It's like when you look at a wobbly floor, and it feels like you might fall over, even though it’s perfectly still!

Your eyes send messages to your brain, like clues in a mystery. Sometimes those clues are tricky or misleading. For example, if you see two circles that seem different sizes, but they’re actually the same size, your brain gets confused because of how the lines around them make it look otherwise.

Think about when you stare at a black-and-white picture and then look at a white wall, suddenly, you see gray shapes. It's like when you take off your socks after being in the bathtub; they feel cold, even though they're just room temperature! Your brain uses tricks to help you make sense of what you’re seeing, sometimes it makes mistakes, and that’s where optical illusions come from!