Optical dilusions

I have to pass on a couple of optical illusions that I ran across. Our eyes actually don't see things perfectly like cameras. Instead they have to report to the brain the partial data that they see, and then the mind interprets it from both eyes, and if it doesn't make sense, scans again quickly and tries to fill in the information that does not compute.

It does this quickly and uses experience and memories of previous images as the comparison. If the images, such as the two concentric circles below, contain so many false clues, the brain just can not resolve it correctly. but keeps trying as you look at different areas.


Click the image for circle validation.

Here is another one: It is an animatied .gif image of only two frames, alternating, but your mind dearly wants it to be going around like a ferris wheel, because that's what makes sense. However it can't decide which way it is rotating. Look at the right and left edges: