Following closely on the heels of "Sweet Eris' nipples, we have Taste Buds in our Lungs", we have this intriguing story.
http://io9.com/5707352/the-size-of-your-brains-visual-cortex-determines-whether-optical-illusions-fool-you
(http://cache.gawkerassets.com/assets/images/8/2010/12/500x_fig_2.24.jpg)
I can force myself to correct the optical illusion by 'void-focus', or focusing through the image or on the background, and then re-focusing on both center circles at once. There was a time I couldn't do that, but nowadays, every time I run into an optical illusion, I try to "see" it both ways by conscious effort.
Stupid contrast effect! :argh!: Why do we have that?
Yeah, if I focus on the center circles I get fooled, but if I kind of unfocus my eyes and see the whole picture, it becomes apparent.
What's the optical illusion in that one supposed to be? Center circle on the right is larger?
I believe so.
After staring at it for a couple seconds, I lose the ability to see the illusion. :(