From the cigar nestled in the brickwork to 'The Dress', many optical illusions have left viewers around the world baffled over the years. But the latest illusion is arguably one of the most bizarre ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. The Vienna team stitched ...

Spot the hidden penguin among the ducks in this optical illusion and test your observation skills in 15 seconds ...