Masawaiyh

Yuhanna ibn Masawaih (circa 777–857), (Arabic: يوحنا بن ماسويه), also written Ibn Masawaih, Masawaiyh, and in Latin Janus Damascenus,[1] or Mesue, Masuya, Mesue Major, Msuya, and Mesuë the Elder was a Persian[2] or Assyrian East Syriac Christian physician[3][4] from the Academy of Gundishapur.

According to The Canon of Medicine for Avicenna and 'Uyun al-Anba for the medieval Arabic historian Ibn Abi Usaybi'a, Masawaiyh's father was Assyrian and his mother was Slavic.

[5] Born in 777 CE as the son of a pharmacist and physician from Gundishapur, he came to Baghdad and studied under Jabril ibn Bukhtishu.

It was reported that Ibn Masawayh regularly held an assembly of some sort, where he consulted with patients and discussed subjects with pupils.

[6] Many anatomical and medical writings are credited to him, notably the "Disorder of the Eye" (Daghal al-'ain), which is the earliest Systematic treatise on ophthalmology extant in Arabic and the Aphorisms, the Latin translation of which was very popular in the Middle Ages.