Optical Illusion - Circles

[Psaumure]

yes, that one was designed for older eyes. We will see how Bill does with it. I'm not sure about the rules that you are referring to. Are you asking about rules on how to see the illusion work or how to draw the optical illusions?

Paul

[Rik]

... 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!

It's the light and the dark bits that trick your eyes into thinking that there is movement.
Here, I've removed the coloured circles leaving just the black and white bits.
You should still be able to see the same movement as my original post.

[gracehjs]

None of them work for me. But I cannot see Gary's stereograms either.

[Soquili]

I'm with Grace about none of these work for me.

However I can easily see Gary's stereograms.

[Rik]

Sorry that some of you can't see this one.
Some expert probably knows why that is?!