Rome - An Italian researcher says the key to solving the enigmas of Mona Lisa lies in her eyes.
Silvano Vinceti claims he has found the letter "S" in the woman's left eye, the letter "L" in her right eye, and the number "72" under the arched bridge in the backdrop of the painting.
According to the researcher, the symbols open up new leads to identifying the model, dating the painting and show that Leonardo da Vinci had an interest in religion and mysticism.
The symbols are not visible to the naked eye. Vinceti said on Wednesday that they are "very small, painted with a tiny brush and subjected to the wear and tear of time."
A Da Vinci scholar has expressed doubt on the new findings, calling them "unsubstantial."