ὅτε: causal, quum, quando, since.
μεγέθη: objects of any size, magnitudes. Cf. Phil. 41 e ἐν μὲν ὄψει τὸ πόρρωθεν καὶ ἐγγύθεν ὁρᾶν τὰ μεγέθη τὴν ἀλήθειαν ἀφανίζει in vision, the near and distant seeing of mag- nitudes obscures the true proportions, Phaedo 111 d καὶ ἀενάων (ever-flowing) ποταμῶν ἀμήχανα μεγέθη.