There could be a scientific explanation for why it seems like some of the world鈥檚 greatest artists saw things a little differently than most people.
Researchers have previously found evidence that Picasso and Rembrandt may have been affected by strabismus, the condition that causes eyes to cross and reduces depth perception.
Leonardo da Vinci may well be another name for that list, according to .
Christopher Tyler, an optometry and visual studies professor at the University of London, started looking at depictions of da Vinci to see if they showed the same consistent eye divergences seen in other renowned artists.
He told CTVNews.ca that finding source material was the biggest challenge he faced.
鈥淭he difficulty with da Vinci is there are so few established self-portraits or portraits of him,鈥� he said Wednesday in a telephone interview from London.
Given the lack of artwork in which da Vinci was described as the subject, Tyler had to get creative. He studied a bronze statue created by da Vinci鈥檚 mentor, Andrea del Verrocchio, for which da Vinci is believed to have served as a model and which Tyler called the 鈥渕ost plausible鈥� surviving example of his likeness.
鈥淚t has clearly divergent eyes,鈥� he said. A similar second sculpture was also studied.
In addition, Tyler researched several of da Vinci鈥檚 works 鈥� a decision he says is backed by da Vinci鈥檚 own belief that artists subconsciously model their subjects to look like themselves.
鈥淗e himself makes the point that it鈥檚 very difficult to avoid doing that, if you鈥檙e an artist,鈥� Tyler said.
Da Vinci wrote in his 鈥淐odex Atlanticus鈥� that 鈥淸the soul] guides the painter鈥檚 arm and makes him reproduce himself, since it appears to the soul that this is the best way to represent a human being,鈥� according to a translation cited in Tyler鈥檚 study.
Tyler found that all seven pieces he examined showed their subjects鈥� eyes to be slightly askew. On average, one pupil was angled about 10 per cent away from where it would be in a non-cross-eyed person.
While Tyler admits that his evidence is circumstantial, he is not the first researcher to try and connect famous artists鈥� works with their appearances. Researchers from Harvard Medical School used a similar method to suggest Rembrandt may have had strabismus.
Margaret Livingstone and Bevil Conway noted in 2004 that having eyes out of alignment 鈥� which would have harmed his depth perception and therefore made it easier for him to depict three-dimensional scenes on two-dimensional surfaces.
Tyler sees the same phenomenon potentially occurring with da Vinci.
鈥淸Strabismus] 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,鈥� he said in the study, which has been published in the journal JAMA Ophthalmology.
According to the American Association for Pediatric Ophthalmology and Strabismus, an estimated four per cent of Americans have strabismus.
