Mona Lisa painting is watching you.
A friend of mine come back from a very satisfying tour from Europe recently and start to describe to me how eerie the painting of Mona Lisa at Musée du Louvre is. “The eyes follow you around no matter which angle you are viewing it from” he said. This phenomenon has to do with the way a painting is created and the lack of third-dimensional on a 2-dimension surface such as a canvas. The key mechanism at work here is perspective.

