Visual I/O Error: Optical Illusions

Optical illusions are a lot of fun – especially the really good ones that you keep staring at and continually have to glance twice.  Remember those cyan and magenta autostereograms that were supposed to be a sailboat if you “just look past the image” or some baloney?  Yeah, never saw the stupid boat, ever.

Optical illusions are miscommunicated signals to the brain that are different than our normal cognition of the item in question, essentially.  Some illusions deal with lengths, some play on the way our brain processes color, and some are just extremely complicated.  Others are not complicated at all, but appear to be complicated.  I’ve never seen the “waterfall illusion” mentioned by Bach and Poloschek (pdf link fyi), where if you stare at a waterfall for a few minutes, objects around the waterfall appear to be moving upward.  But the illusion with the blinking pink dots chasing around the center of a point – where if you stare at the center, the blinking chasing dot turns green, is a very vivid illusion for me.  You know the one, like this:

I found a bunch of illusion images.  Which ones work for you?

The lines below this image are completely parallel:

The square labeled “A” is exactly the same gray as square “B” – seriously!

These rows are completely straight, but appear wavy:

Here’s some just to bug your eyes out:

Thanks, Dr. Bach!