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Try the follow the spiral by tracing just above it with a pen or the tip of your finger. You can’t. Why? Because what you’ll be seeing is not a spiral but a set of circles. Yes, really. Check it out.
How It Works
This illusion was created by British psychologist James Fraser, who first published it in 1908. When you look at the Fraser Spiral it appears a single line is twisting its way into the center, spiraling into a funnel. Your eyes, Judas-like, are deceiving you. The Fraser Spiral works by guiding the eye through a sequence of counter-angles. The eye and brain are not accustomed to processing images this geometrically complicated, and thus try to normalize the circles by imagining them as a single line, a phantom spiral corkscrewing its way to the center.