Optical illusions

This post is for publishing some curiosities about vision:
Motion silences awereness of color changes from Jordan Suchow on Vimeo
Instructions: Keep your eyes fixed on the small white mark in the center. At first, the ring is stationary and it's easy to tell that the dots are changing. A few seconds later, the ring begins to rotate and the dots suddenly appear to stop changing.
For most people, when the dots start to rotate, they either completely stop changing colour, or they hardly change colour at all. However the reality is that the dots are still changing colour, just as they were before they started rotating. Even when you know that the dots are changing colour, it does not affect the way you see the illusion.
So when an image of an object moves across our retina, our ability to detect changes in that object is substantially diminished.
If you like it, this link has several examples.
This optical illusion has been created in three dimensions. It is a real object. However impossible things seem to happen! The wooden balls seem to roll uphill. It cannot be magnets - they do not work on wood! This wonderful illusion was created by Koukichi Sugihara from the Meiji Institute for Advanced Study of Mathematical Sciences in Japan.
However once the structure rotates, we can see that it is not constructed as we initially thought. We might have thought that the wooden balls were rolling uphill. Once we view it from the other side, we can see that in fact the balls are rolling downhill, and that the laws of physics are still being obeyed. Whew!
In this webpage there are other videos about brain illusions
I suppose you already know M.C. Escher and his amazing drawings. This tower is from Hungarian artist István Orosz. The tower is like a Möbius Strip.