Unless otherwise indicated, images on this page are from Akiyoshi's illusion pages (2002 to 2011) © by Akiyoshi Kitaoka. At http://www.ritsumei.ac.jp/~akitaoka/index-e.html. (used with permission)
Hinton's “Lilac Chaser” By Jeremy L Hinton, Michael Bach. At http://www.michaelbach.de/ot/col_lilacChaser/index.html
This website is really trippy, at: Source www.neave.com. It demonstrates motion after effect, which is not entirely understood.
Math and Illustrations
If you have a question, put $5 at patreon and message me.