Petrus Lusitanus (1213-1277), author of Liber de Oculo, was the only ophthalmologist to become Pope (1276). His book, not well-received, was probably written while he was professor of medicine in Siena. It has more importance because it was one of the first books written in the Italian language. His papacy lasted only 8 months, ending with his death from the collapse of a palace roof. Pope John XXI was the only Pope mentioned in Dante's Divine Comedy and he was placed in heaven by the poet.
A look at the past . . .. Arch Ophthalmol. 1999;117(3):419. doi:10.1001/archopht.117.3.419