Prepare to lose your grip on reality: the winners of the Best Illusion of the Year Contest have been revealed. First prize was bagged by Kokichi Sugihara, a mathematician at Meiji University in Japan who has won a number of prizes from the contest in previous years. This year, he was awarded for his optical illusion “3D Shröeder Staircase.” A Schröder staircase is a classic optical illusion that shows a two-dimensional picture of a staircase that can be perceived either as a drawing of a staircase leading downwards from left to right, or an upside-down staircase. Sugihara took this idea and turned it into a three-dimensional model.