Magic cylinder

http://www.echalk.co.uk/amusements/OpticalIllusions/colourPerception/colourPerception2.html

click illusion 1. Weird......

I'm gonna buy one of those cylinders and place it near the board when I play Akizy again! 😛 😉

Asked a friend to look at the spiral pinwheel illusion. Told him to keep
looking at the center and an image will appear. After having looked at the
center for about 30 seconds, I yelled:

-Oh my GOD! What's happening to your hand!?

He went:

- hhhhhhhh!!! 😲

I haven't laughed so hard in a long time. 😀

My wife was teaching a lesson about optical illusions so I bought her one of these:
http://www.hawkin.com/find/keyword-is-expanding/product-is-09699

It works really well and makes a change from the usual pictures which are used to illustrate optical illusions.