7. Spiral
Spiral rainbow. Does it move for you? Does it make you feel groovy? (Or nauseated?)
8. Shelves
A visual cognitive illusion is the result of unconscious inferences we make based on our assumptions about the world, i.e. our expectations. First explained by Hermann Helmholtz, this type of illusion can continue to confuse you even when you know the trick. Case in point: how many shelves are there?