How to improve your sight without glasses

This is a fabulous solution. You don’t have to make an appointment with an ophthalmologist or an optician. In fact, it costs you nothing.

Optical illusion

This amazing little video was produced by pointing a camera at a real-world scene composed of four tracks that guide the movements of rolling marbles:



As soon as the table is turned around, providing you with a view of the scene from the opposite side, you can immediately see the tricks behind the illusion. The tracks simply slope downward towards their intersection, and they're designed in such a way that, when viewed from a certain angle, they seem to slope upward. The creator of this excellent illusion is Koukichi Sugihara of the Meiji Institute for the Advanced Study of Mathematical Sciences, Japan.