spiral aftereffect
Dark Spiral Illusion
Here’s a beautiful spiral illusion. As the pattern spins in this gif, you can feel yourself sink into the spiral. The spiral aftereffect is also strong! Here’s what the graphic looks like when it’s not spinning:
The Spiral Tornado Illusion
The Spiral Tornado Illusion — Look at this spinning tornado for a few minutes and then look away at a strong pattern. Watch the pattern twirl and buzz! This is known as the spiral aftereffect. Also, check out this larger version. It also works very effectively.