He made predictions and observations of solar and lunar eclipses in 364 which show he was active at that time, and he is said to have lived during the reign of Theodosius I (379–395).
[2] The Suda, a tenth-century Byzantine encyclopedia, calls Theon a "man of the Mouseion".
[4] Theon's school was exclusive, highly prestigious, and doctrinally conservative.
[4] Neither Theon nor his daughter Hypatia seems to have had any connections to the militant Iamblichean Neoplatonists who taught in the Serapeum of Alexandria and instead preferred Plotinian neoplatonism.
The editions ascribed to Theon are: Of his commentaries, those which are extant are: Among Theon's lost works, the Suda mentions On Signs and Observation of Birds and the Sound of Crows; On the Rising of the Dog[-Star]; and On the Inundation of the Nile.