The word illusion originates from the Latin verb illudere, meaning to deceive or hide. Optical illusions are intriguing and test mental sharpness. An image challenge of a camouflaged cat within a potted plant is provided for readers to solve within nine seconds. Successfully spotting the cat indicates high visual acuity.The word illusion originates from the Latin verb illudere, meaning to deceive or hide. Optical illusions are intriguing and test mental sharpness. An image challenge of a camouflaged cat within a potted plant is provided for readers to solve within nine seconds. Successfully spotting the cat indicates high visual acuity.