Experts believe the famous Mona Lisa artwork may be unfinished.
It's thought Leonardo da Vinci had a severe fainting episode leaving him with a "claw" hand, unable to hold a paintbrush.
A portrait of the artist shows his right hand wrapped in bandages.
Even though da Vinci drew with his left hand, he painted with his right too.
Rsearchers believe the injury may have forced him to leave many works incomplete.