Leonardo da Vinci could have been a divergent strabismus. That is the conclusion reached by a British neuroscientist after analyzing several alleged portraits and self-portraits of the painter. It goes even further: the exotropia would have given the Italian master his brilliant ability to represent depth on flat surfaces. However, both paleopathologists and ophthalmologists consider it risky to diagnose that da Vinci had strabismus only by looking at some pictures in which it is not even known with certainty if he acted as a model.
If the ten works analyzed in the studio could be brought together in the same room, they would further fuel the fantasies and legends that surround the Italian genius. Three statues made by Andrea del Verrocchio when da Vinci was his disciple used the same person, or a very similar one, as a model. In all three it is seen that one of the eyes has a deviant look. For many, including the specialist in visual neuroscience and author of the study, the professor of the University of the City of London Christopher Tyler, the person who appears in marble or terracotta is a young Leonardo.
The ocular deviation or exotropia is more evident in two of Leonardo's paintings, his Saint John Baptist, painted around 1508-1513, and the Salvator Mundi, the most expensive work in history. Even in two of his mythical drawings, the Renaissance Vitruvian man and his Self-portrait, already old, Tyler appreciates some ocular divergence. For him, there is no doubt that the person who appears in the different works had divergent strabismus. It even estimates the angle of deviation observed in each of the works.
The study assumes that the man represented in statues and paintings is Leonardo himself
Of the different degrees of divergence, Tyler infers that da Vinci could control his strabismus. "The analysis of the alignment of the eyes agrees with a diagnosis of intermittent exotropia, which suggests that Leonardo da Vinci had an exotropic tendency of about -10.3º in rest, but I could go back to orthotropy [ambos ojos miran al mismo punto] when he focused, like when he reviews his own face for a self-portrait, "Tyler writes.
In the study, published in JAMA Ophthalmology, the British researcher explains that intermittent exotropia "is usually associated with good stereoscopic vision when the eyes are straight" but is lost when the eye is deflected. they deviate. "If you see the world with only one eye, due to the suppression of the other when it deviates, the visual scene seems much flatter and, therefore, easier to transfer to the canvas," says Tyler. So having a poor binocular vision could be an advantage when it comes to taking three-dimensional scenes to a surface.
"This type of retrospective diagnosis is risky and, in my opinion, quite naive", criticizes Michael F. Marmor, professor of ophthalmology and human biology at the Byers Eye Institute of Stanford University (USA). And it is for several reasons. "First, it is doubtful that these works represent da Vinci The relationship between these works is very circumstantial and doubtful and all the faces look different!" He adds. "Artists make mistakes in their self-portraits: Rembrandt changed the position of the eye, Van Gogh painted his own sometimes blue, sometimes green and even brown Artistic licenses rule and the eyes were, I suspect, added to the painting at the last moment. But yes, even the photographs of normal people show some strabismus when they look to the side ", completes the author of the book The Artist's Eyes (The eyes of the artist, not edited in Spanish).
Marmor also rules out that, in any case, the strabismus will bring something to da Vinci. "Those of us with normal vision do not have problems to see the two-dimensional images of books or photographs, and artists with a good perception of depth do not have them to paint them." The few strabismic artists that are known to be, like Dürer or Barbieri, Il Guercino, "they painted wonderful works with fine perspective," he explains.
The Italian paleopathologist Francesco Gallasi uses historical records to diagnose ills that afflicted characters of the past, such as Julius Caesar, the Visigoth king Alaric I or Dante Alighieri. But, in the case of da Vinci, he believes that the British scientist is going too far. "What can be said about this ophthalmological study is that in Leonardo's works there are interesting examples of ancient representations of strabismus, but to consider these works as authentic self-portraits of the teacher seems to me exaggerated," he says. For Gallasi, only if it were found where Leonardo da Vinci is buried would there be a possibility to diagnose his illnesses. But he does not believe that "the complex nature of genius can be reduced to simple biological elements".