New Delhi, July 5 -- There's no better way than optical illusions to challenge your brains! And this award-winning optical illusion, which is making a viral comeback, is bound to have you scratching your head. Known as the Coffer Illusion, it may look like a simple grid of black and white rectangles, but hidden within are 16 perfectly round circles. Can you spot them?

According to a BBC report, the optical illusion was created by Stanford vision scientist Anthony Norcia. It was crowned Best Illusion of the Year in 2006. At first glance, most people only see rectangular shapes arranged in a tiled fashion.

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According to the Guardian, t...