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One such illustration by Hungarian illustrator and graphic artist Gergely Dudas has gone viral on the internet.

Optical illusion

Optical illusions are both captivating and intriguing as they challenge our visual perception and cognitive capacities. They are also known as visual illusions and often used as easy IQ tests in pop culture. 

Literal illusions happen when our brains perceive an object's physical characteristics wrongly. The manner in which our eyes and brains observe light and colour leads to physiological illusions.