LitDev, a very active Small Basic Forum participant has started a thread with a bunch of Small Basic programs that illustrate fascinating optical illusions. Here are some below – click on the link below the images and you can actually view them on your browser.
http://smallbasic.com/program/?PVC930
http://smallbasic.com/program/?CDV606
http://smallbasic.com/program/?FMW356
http://smallbasic.com/program/?CNR593
http://smallbasic.com/program/?TTR706
Go check out the forums for more updates. You would need to download the latest version of Small Basic to be able to modify and create new illusions.