Mona Lisa in 3-D?

The discovery of a Mona Lisa twin in the Museo del Prado in Madrid has led art historians and scientists to consider if Da Vinci's most famous work was actually the world's oldest 3-D artwork. (photos)

"When I first perceived the two paintings side by side, it was very obvious for me that there is a very small but evident difference in perspectives," study researcher Claus-Christian Carbon of the University of Bamberg in Germany wrote in an email to Live Science.

Claus-Christian Carbon and his fellow researcher Vera Hesslinger of the University of Mainz looked at the arts and created their owb 3-D effect image which is available to view online.