The eyes of Leonardo da Vinci’s iconic Mona Lisa have long been thought to follow viewers around the gallery of the Louvre Museum in Paris where it is exhibited, as well as those looking at photographs and reproductions of the famous painting. Now, researchers from Germany's Bielefeld University assert that while “The Mona Lisa Effect” – the impression that the eyes of the subject in a portrait are following the viewer – is real, it is not true for its namesake painting.