How do optical illusions work?

[misskitty]

I think this is the forum this question belongs in. I was looking at this shifty red pen I have and I though about an optics and light question. How do optical illusions work? Is there some kind of physics theorum or idea which would explain how this works? I hope this makes sense.

 

[Integral]

You will need to provide an example of a specific optical illusion. There are many different examples of optical illusions and nearly as many different explanations.

 

[cronxeh]

If you are talking about optical illusions in pictures like the one on http://www.optillusions.com/

I think most of those are more of a human psychology question - but there is physics involved in the interpretation of the image by your brain.

 

[russ_watters]

If you're talking about how you can wiggle a pen and make it look like its bending, that's probably because your eyes can't track the different parts of the pen moving at different speeds - and moving too fast for your eye to follow.

 

[misskitty]

I wasn't talking about wiggling the pen and make it look like its bending. How about the picture of the two ladies and the vase? The black and white picture with the two black figures on the sides that look like a young lady and an older lady and in the white in the middle it looks like a vase. Integral, would that work?