He wrote commentaries on Aristotle's second book of the Analytica Posteriora and the Ethica Nicomachea.
[2] A few years after the trial of Italus, he wrote a dialogue and treatise on the use of icons directed against Leo, the bishop of Chalcedon, who had accused the emperor Alexios I Komnenos of sacrilege and iconoclasm in the way in which he had stripped the churches of gold to fund his wars.
[3] For this he gained the emperor Alexios I's friendship, and this probably helped him to become Metropolitan bishop of Nicaea.
Eustratius was said by Anna Comnena to have been wise both in mundane and in religious matters and especially expert in argument.
[2] As a result of the condemnation Eustratius was formally suspended for life.