He became director of a hospital in Baghdad, and was personal physician to four caliphs. He composed medical treatises on a number of topics, including ophthalmology, fevers, leprosy, headache, melancholia, dietetics, the testing of physicians, and medical aphorisms. One of Masawaiyh's treatises concerns aromatics, entitled, On Simple Aromatic Substances.
It was reported that Ibn Masawayh regularly held an assembly of some sort, where he consulted with patients and discussed subjects with pupils. Ibn Masawayh apparently attracted considerable audiences, having acquired a reputation for repartee.
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.[6]
J.-C. Vadet, "Ibn Masawayh" in, The Encyclopaedia of Islam, 2nd edition, ed. by H.A.R. Gibbs, B. Lewis, Ch. Pellat, C. Bosworth et al., 11 vols. (Leiden: E.J. Brill, 1960-2002) vol. 3, pp. 872–873
Manfred Ullmann, Die Medizin im Islam, Handbuch der Orientalistik, Abteilung I, Ergänzungsband vi, Abschnitt 1 (Leiden: E.J. Brill, 1970), pp. 112–115
Fuat Sezgin, Medizin-Pharmazie-Zoologie-Tierheilkunde bis ca 430 H., Geschichte des arabischen Schrifttums, Band 3 (Leiden: E.J. Brill, 1970), pp. 231–236.
^V.C. Medvei, The History of Clinical Endocrinology, p. 45.
^Irwin, Robert, ed. (2010). The new Cambridge history of Islam, Volume 4 (1. publ. ed.). Cambridge: Cambridge University Press. p. 663. ISBN978-0-521-83824-5.
^ abcdeSarton, George (1927). Introduction to the History of Science, Volume I. From Homer to Omar Khayyam. Baltimore: Carnegie Institution of Washington. p. 574. OCLC874972552.