One very famous optical illusion is the formation of a rainbow. Of course, it doesn’t really exist in the sky, but our eyes perceive its colors based on where the sun is. The answer why is quite complicated, but the gist is that our brains often make premature assumptions about what our eyes see. And it has been proven that our eyes can be fooled very easily.
Bright Side collected 11 optical illusions that will keep your brain in a confused state for some time.