Optical Illusion - Circles

[Rik]

Surely this one will move for Larry?!

[wizard509]

Cool Rik, but I'm afread not. I don't know if it's my monitor or what the problem is. I used to see those things move but not now.

[angelize]

very cool Rik! It moves for me!

[Rik]

Cool Rik, but I'm afread not. I don't know if it's my monitor or what the problem is. I used to see those things move but not now.

Age?!

Thanks for your kind comments Frances.

[Soquili]

It could be age, I also cannot see them move.

[Rik]

I was only joking with Larry, but, I am going to have to take your comment a bit more seriously Bill.
Only because that's two people saying the same thing.

If you click on the image in the post, it should enlarge.

Then when you are looking at it, the moving effect only happens if you move your eyes from one part of the image to another.
If you keep your eyes perfectly still and staring at just one point, then nothing moves.
So, the movement of your eyes plays an important role in the illusion.

[Soquili]

Rik I can remember seeing similar images that would seem to move but that was some years ago.

I've tried several methods of viewing them but cannot see movement now. Age is the only thing I can think has changed.

[wizard509]

Hummmmmm. I guess Bill has a problem. But not me I refuse to get old

[Psaumure]

Rik, I can see it move but it does take a little work.

I enjoy working with optical illusions. I had posted some puzzles about a year ago. This one does not move in circles but I had a hard time putting it together because it continue to draw my eyes in as I was drawing it.

[edm3]

Wow - that one really is hard to escape Psaumure!
I see the effect in the circular one Rik - it's just less obvious to me.

Is there a rule/set of rules that make these optical illusions work? Kind of a sweeping question, but I'm asking from close to point zero!

Cheers!