Are your eyes playing tricks on you? Maybe they are if you are using this set of fun optical illusions! Did you know that concentric circles can look like a spiral, red can be green, and shapes can float? Explore 3D images and even create your own! Entertaining set includes a booklet with 21 classic illusion tricks and explanations, 3D glasses, a spinning top with four pattern sheets, 3D drawing markers with a special holder, a travel pouch, and instructions.