Seeing is believing, right? Well, in the case of optical illusions, you might find it hard to believe what your eyes are telling you. Objects that seem to be different sizes are really identical; pictures move on the page; images that appear one way suddenly become something else altogether. Don't run off to the optometrist. This is all part of the fun and the mind sharpening powers you get when trying to solve the challenges in Brain Games: Optical Illusions.