Spent a few hours working on this. Yes, I had a migraine afterwards. Yes there were moments when I felt green and had to look away. Most of those moments came along during the last hour, when the majority of the piece had been finished, and I could begin to see a bit of movement even when I was up close on it. I took some excedrin and had a few drinks after work, that helped bring me back to normal. My eyes were skewy for a few hours after I was done working.
It was a challenge and I am so stoked that I got to do this! I love anomalous motion illusions. I really wanted to do at least one of them, try to make it work on skin. This was a good start. I’ve got a few more of these on the way.
What an awesome day!
Why these work: Your brain sees the shadow of the shapes, or areas that converge, as possible movement. Since there’s a lag between your eye seeing it and your brain understanding it, images like this appear to move. Your peripheral vision and your direct focus have a time lag as well.
Your brain interprets the image as conatining motion. In this one people may see radiating spikes of shadow that move around, or motion into or out of the center, or vibration.
Anomalous motion is your mind playing tricks on you, basically.