How this triple illusion will make you see an ‘expanding black hole’

The illusion of an “widening aperture” may trick your brain into thinking you are walking in a cave or tunnel. (image credit: Frontiers in human neuroscience)

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An entirely new optical illusion tricks the majority of people into thinking that a dark “black hole” region in the center of a still image is rapidly expanding, as if the observer were moving toward it. Researchers now suspect the image is literally deceiving brain In thinking that the observer is moving to a dark place, such as a cave or a tunnel.

The illusion consists of a large black oval surrounded by a dark halo on a white background filled with smaller black edges. Normally, when a person stares at an image, the dark elliptical region will appear to be expanding outward for a few seconds, which is why the design is called an “expanding aperture.”