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What: This optical illusion serves as an alternative instance of the “Fraser spiral” or “concentric spiral” illusion. It was named by British psychologist James Fraser in 1908. Even though it doesn't have rounded “loops”, the visual interference generates similar lines, resulting in the same effect. As you might have already sensed from the overall impression, this is a recreation by Akiyoshi Kitaoka. However, I've added the spinning feature to intensify the effect, along with customizing the colors. As a nod to a previously created illusion, this effect isn't significantly different from the “spirals but not spirals” .

How To: If you're looking at this illusion and seeing or perceiving a spiral, then you're experiencing it. Here, only circles are drawn, accompanied by numerous additional squares and background noise to enhance the effect. You can click on the settings to change the colors and the number of circles or steps, enabling you to discover different critical points. Initially, I've set it up according to the original illusion design. But I've found that there are multiple different combinations with more or fewer spirals, larger or fewer diamonds, and different colors that can, so to speak, make my brain fully perceive a spiral.

Explain It: The visual distortion is created by combining a regular line pattern (in this case, the checkers) with the distortion caused by the black - and - white squares that alternate in color as the rings get deeper. Additionally, the background and the movement further contribute to it [4]. Your peripheral vision does the remaining work. It's all too overwhelming to take in and process easily, so your brain fills in the blanks, and you end up perceiving a “spiral”. Akiyoshi is a master at using these techniques in colorful and vivid ways, which is evident in this illusion.