Quoted in Jonathan Franzen’s The Corrections:
If the eye were an animal, sight would be its soul
Google tells me that is from De Anima 412b (near the beginning of Book II):
εἰ γὰρ ἦν ὁ ὀφθαλμὸς ζῷον, ψυχὴ ἂν ἦν αὐτοῦ ἡ ὄψις· αὕτη γὰρ οὐσία ὀφθαλμοῦ ἡ κατὰ τὸν λόγον (ὁ δ’ ὀφθαλμὸς ὕλη ὄψεως), ἧς ἀπολειπούσης οὐκέτ’ ὀφθαλμός, πλὴν ὁμωνύμως, καθάπερ ὁ λίθινος καὶ ὁ γεγραμμένος.
… that is, a sightless eye is an eye in name only, like the eye of a sculpture or drawing. The eye is the “matter” of seeing, its physical part.
It’s hard to know what to make of such texts. When an author like Aristotle speaks of the “soul”, there’s no reason whatsoever to think he means what we would mean. A translation is thus not very helpful. But the idea of the eye as a furry creature running about is Pythonesque.