The Mona Lisa by Leonardo da Vinci has to be one of the most, if not the most, recognized paintings ever. Even ask an elementary school-aged child and most likely he or she will know that she is a painting, and may even get part of the name correct. This cannot be a fluke. Somehow, da Vinci was able to paint a face that would not only create an emotional appeal but also be remembered by people of all ages and backgrounds. Surely, there are many women models would love to be so lucky. Recently, due to a revived interest in da Vinci, Mona Lisa has been more popular than ever. This in addition, to all the other ways she is seen from being on men's ties to Mad Magazine Throughout the years, there have been all types of theories about her and the painting. If is possible, even more have come out due to this new stardom. It seems that most of these theorizers not only have a hypothesis about her smile or name, but believe that no one else's hypothesis is right except for theirs!.

             The theories about Mona Lisa run the gambit from the most theoretical and nonscientific to the most scholarly and technical. A number of both scientists and social scientists have presented their ideas about Mona Lisa. A few years ago, Margaret Livingstone, a neuroscientist from Harvard, no less, applied her knowledge of the brain and vision to develop a theory about the enigmatic smile. According to Livingstone, da Vinci was playing an optical illusion game on viewers. .

             An area of the retina, or the lining of the back of the eye, called the macula provides humans with central vision, which is used for most vision such as colors, shapes, driving, viewing faces and the like. The items humans see from the sides of their eyes is called peripheral vision. Central vision has high acuity or is very sharp, and peripheral vision has lower acuity and is actually somewhat out of focus. Livingstone says that the main reason why people see Mona Lisa's smile in this particular fashion is because her expression changes depending whether someone looks up at her eyes or down at her mouth.