Our eyes can play various tricks with us. We might sometimes see something or someone which is actually not present there. This phenomenon is called optical illusions. These illusions can trick your brain into perceiving things in a way that might not be true. This happens because our eyes and brain don't always interpret the world perfectly, so we can be fooled by things like weird shapes or colors.
Imagine you look at a drawing that appears to be moving, even though it's just a still picture. Your eyes send signals to your brain, but the brain doesn't always understand these signals precisely. It might make you think the picture is moving, even though it's not.
