For over two millennia, the Parthenon's subtle curves have been celebrated as evidence of ancient Greek optical genius — a story so compelling it outlasted empires and entered the age of artificial intelligence. Now, Oxford mathematician Alain Goriely has done what generations of admirers did not: he tested the claim, and found the illusions the curves were meant to correct either do not exist or are too faint to perceive. The myth, it turns out, may tell us less about how the Greeks built than about how deeply we wish them to have been as wise as we imagine.