Welp, it turns out that your brain doesn't manage well looking at different angled rectangles, and creates a floating disk.
What: The Ouchi illusion is an illusion named after its inventor, Japanese graphics artist Hajime Ouchi [1], in 1977, you’ll notice that the disc in the center appears to hover above the background, and when you’re moving your head it can appear to be moving slightly when in reality we know its static and a fixed 2D circle.
How To: You’ll be able to ramp up the intensity of this one by increasing the contrasting colors (black and white being the original artist’s design), also the length and height of the rectangles can be changed, for me when they are short and long (or long and short) the illusion is strongest. Also if I scroll up and down slightly (adding a little motion) it causes the effect to be much stronger.
Explain it: Perusing around and reading a few papers left me more confused than I began, though I eventually found a great description:
The illusion is caused by random eye movements, which are independent in the horizontal and vertical directions. However, the two types of patterns in the figure nearly eliminate the effect of the eye movements parallel to each type of pattern. Consequently, the neurons stimulated by the disk convey the signal that the disk jitters due to the horizontal component of the eye movements, while the neurons stimulated by the background convey the signal that movements are due to the independent vertical component. Since the two regions jitter independently, the brain interprets the regions as corresponding to separate independent objects [2]
I've researched these optical illusions in my spare time but am clearly not any kind of expert and my explainations are pretty smooth brained, if you find something mis-cited, earlier examples, or general mistakes please new let me know via toymaker@toms.toys, be kind!