Painter, inventor and polymath Leonardo da Vinci may have had a squint that helped him capture the Mona Lisa’s smile and create his masterpieces, The Independent has reported.
Doctors from the Optometry and Vision Sciences School at City University of London have diagnosed the Renaissance master with strabismus after analysing the eye alignment of works believed to have been modelled, in part, on himself.
Strabismus is a common vision disorder where one of the eyes looks inward, outward, up or down when the other eyes is focused on an object.
The condition is thought to be beneficial to painters as it lets them better focus on close-up flat surfaces and has been identified in a number of famous artists, including Rembrandt.
“A number of famous artists have been identified as having strabismus on the basis of the eye alignment evident from their self-portraits, including Rembrandt Harmenszoon van Rijn, Albrecht Dürer, Giovanni Francesco Barbieri (who was also known as Il Guercino, Italian for ‘the squinter’), Edgar Degas, and Pablo Picasso,” the study’s author, neuroscientist Professor Christopher Tyler, said.
“Some forms of strabismus are thought to facilitate artistic work by suppressing the deviating eye, which creates two-dimensional monocular vision advantageous to painting and drawing”
While having two eyes focused on an object (stereoscopic vision) is integral to our depth perception, it can make translating three-dimensional scenes to canvas more tricky, as each eye will be seeing objects slightly to the right or left.
For the study published in JAMA Ophthalmology, Professor Tyler measured the alignment in six art works believed to be partly self-inspired by fitting circles to the irises of each eye and measuring the average deviation from alignment.
Works included two drawings, two oil paintings and two sculptures. Among them his world famous Vitruvian Man sketch, the bronze sculpture David – reputedly a depiction of the young Leonardo– and Salvator Mundi, his painting of Jesus Christ which recently became the most expensive in history.
In all cases, the eye misalignment was measurable, though not severe and averaged a −10.3° deviation from the focussed eye across the six pieces.
This negative number means the eye would tend to look outwards (exotropia) and Professor Tyler argues that da Vanci’s strabismus may have been non-existent when focusing intently on an object, but would come in when he relaxed into painting.
The professor said: “The weight of converging evidence suggests that Leonardo had intermittent exotropia, with a resulting ability to switch to monocular vision.
“This would perhaps explain his great facility for depicting the three-dimensional solidity of faces and objects in the world and the distant depth recession of mountainous scenes.”
