Abstract
There is no systematic physiology of the eye within Alexander of Aphrodisias' commentary on Aristotle's De Sensu that would match the work of Galen in this area because Alexander is interested in the principles that (as he
sees it) guide the work of medical researchers rather than the messy detail of the work itself. If he was aware of Galen’s work in this area, his criticisms of the coalescence theory of vision as set out in the Timaeus is a sufficient answer at the
level of philosophical principle, and the inadequate anatomical detail in Alexander’s own physiology of vision reflects that outlook. Alexander’s physiology is not ultimately to be judged against the criterion provided by the model of Galen’s
dissection-based research.