A centuries-old question about Sandro Botticelli's iconic painting, 'The Birth of Venus,' may have a new answer. Researchers propose that the model for the masterpiece, Simonetta Vespucci, had a brain tumor that caused a squint, a condition depicted in the artwork.

Previously, the uneven eye positioning in the painting was thought to be a symbolic representation of piety and beauty. However, scientists from Queen Mary, University of London, have put forth a different theory based on their analysis of five portraits of Vespucci.

Using a facial recognition algorithm, the researchers identified several indicators suggesting Vespucci suffered from a pituitary adenoma, a common, benign tumor that affects the pituitary gland at the base of the brain. "It's possible that the irregular eye positioning in the Birth of Venus – the 'strabismus' or squint later considered a trait of piety and beauty – may be caused by the pituitary tumor," stated senior author Paolo Pozzilli.

Simonetta Vespucci was a prominent figure in Florentine society and was painted multiple times by Botticelli, who was reportedly deeply admiring of his muse. She died at the young age of 23, and the circumstances surrounding her death have been a subject of speculation.

The new study also suggests that tumor apoplexy, a sudden medical emergency caused by the expansion of an adenoma, was likely the cause of her death. Historical documents reviewed by the team mention her collapsing during a ball, experiencing severe headaches, hallucinations, vomiting, and high fever in her final days. These symptoms, researchers noted, are consistent with a rapidly expanding pituitary tumor.

The facial recognition algorithm not only highlighted the squint but also identified lactation in Botticelli's "Allegorical Portrait of a Woman," also believed to be of Vespucci. Since Vespucci had no children, this feature, along with other facial changes, is interpreted as a possible physical symptom of a prolactin-growth hormone secreting adenoma.

This analysis adds to a growing trend of researchers examining historical artworks for signs of medical conditions. In 2024, a separate study identified potential signs of breast cancer in a figure within Michelangelo's "The Flood" in the Sistine Chapel, suggesting artists may have subtly incorporated such details into their work, possibly as commentary on mortality.

Botticelli's "The Birth of Venus," painted around 1485, is housed in the Uffizi Gallery in Florence. .