The Optical Illusion Hidden In The 'Mona Lisa,' Explained
The woman in Leonardo da Vinci’s famous painting doesn’t always appear to be smiling, thanks to an artistic technique.By Evan Thomas | August 22, 2015
Art historians say Leonardo da Vinci hid an optical illusion in the Mona Lisa’s face: she doesn’t always appear to be smiling.
There's question as to whether it was intentional, but new research into a second painting attributed to da Vinci suggests yes, it was.
"Portrait of a Young Fiancée," which is thought to be of an Italian girl named Bianca, shows the same almost-smile depending on viewing distance and sharpness of the image.