That鈥檚 the question I ask when I see a claim purporting that some supplement prevents or cures disease, or a cream that is said to reverse skin aging, or an environmental contaminant that supposedly marshals us towards a premature encounter with the undertaker. I鈥檓 all about evidence. That鈥檚 why I was intrigued by the title of a paper that appeared in 鈥淥pthalmology,鈥� one of the American Medical Association鈥檚 peer-reviewed journals. That title was 鈥淓vidence That Leonardo da Vinci Had Strabismus.鈥�
Strabismus, often called 鈥渃ross eyes,鈥� is a condition in which the eyes are misaligned. One eye deviates either outward (exotropia), or inwards towards the nose (esotropia), while the other eye remains focused. Commonly vision with the misaligned eye is suppressed, meaning that some three dimensionality is lost. Some people afflicted with strabismus can revert to proper alignment just by being attentive, allowing them to then see everything properly in three dimensions. The author of the paper, Christopher Tyler from the City University of London, contends that da Vinci had intermittent exotropia, meaning that he had the ability to either view a scene as flat, which would be useful when working on a flat canvas, or by being attentive to his vision, see things in three dimensions, allowing him to add perspective to his painting.
An interesting premise. But what鈥檚 the evidence? Tyler bases his argument on measuring the angle of deviation of one eye from normal in six works of art he claims depict da Vinci鈥檚 face in some way. Only one of these is actually a self-portrait and Tyler admits that the alignment angle is hard to determine due to occlusion by the bushy eyebrows and partial turn of the head.
Two of the other five works are statues purported to be of Leonardo by a sculptor with whom he had apprenticed.
Three others are paintings by da Vinci that are not self-portraits but supposedly incorporate some of his own facial features. That argument is based on one of da Vinci鈥檚 writings in which he states that 鈥渢he soulnguides 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� Tyler takes this to mean 鈥渢hat any of Leonardo鈥檚 portraits may be considered to reflect his own appearance to some extent.鈥� The operative word her is 鈥渕ay.鈥�
One of these portraits is 鈥淪alvator Mundi鈥� or 鈥淪aviour of the World鈥� that depicts Jesus head on and at $450 million is the most expensive painting ever sold, supposedly purchased by proxy for Saudi Arabian crown prince Mohammed bin Salman. The painting鈥檚 current location is unknown but it is rumoured to be on the prince鈥檚 yacht.
Da Vinci鈥檚 painting of 鈥淵oung John the Baptist鈥� hangs in the Louvre and Tyler believes this also features the artist鈥檚 face, and finally there is Leonardo鈥檚 famous drawing, 鈥淭he Vitruvian Man鈥� that represents his conception of the ideal body proportions and even appears on the Italian one Euro coin.
Dr. Tyler closely examined the eyes on these six works of art and determined that they all showed some degree of misalignment with one eye wandering away from the nose, giving rise to his conclusion that da Vinci suffered from strabismus. Maybe 鈥渟uffered鈥� is the wrong word here, because according to Tyler the affliction was to the artist鈥檚 benefit.
To recap. The two statues are purported to be of Leonardo without any supporting documentation, the eyes are not clearly seen in the one true self-portrait, and that Leonardo incorporated his own features into his paintings is pure conjecture. The Mona Lisa has also been purported to be a self-portrait but this was not mentioned in the 鈥淥pthalmology鈥� paper since she is clearly not cross eyed.
So when it comes to 鈥淓vidence That Leonardo da Vinci Had Strabismus,鈥� let me ask the question, 鈥渨here exactly is that evidence?鈥�
