Rotating zabuton by Akiyoshi Kitaoka Each checkered background consists of squares but appears to be distorted like a bulge or concave. In addition, these figures show a retinal-slip-dependent anomalous motion illusion as well as a pattern-dependent rotating illusion.
Levitating Circle | Mighty Optical Illusions
Math is a human language that describes nature.
Optical Illusion is Visual Reality by Kurtz Graphic Design Co
World's All Amazing Things, Pictures,Images And Wallpapers: Optical Illusion - Amazing Optical Illusion
Resolving Confusion Over the Met Office Statement and Continued Global Warming
Eye Tricks Scary Optical Illusion | Cool stuff.....due in part to exact complimentary color usage.
References for various fundamental things - composition, balance of details etc. I don't have sources for most of these as its something that was lying on my hdd for a while, but you should be able to look it up through google images.
Halftones Pack – 55 Free Vectors, Brushes, and Images