ὦ ξεῖν̓. The Ionic voc. occurs even without metrical necessity, Eur. I. T. 798 “ξεῖν̓, οὐ δικαίως”: Soph. rarely uses ξεῖνος except in voc.: 1014 n. ὑπέρ τ᾽ ἐμοῦ=ὑπὲρ ἐμοῦ τε: as O. T. 258 (where see n.), “κυρῶ τ᾽ ἐγώ”=ἐγώ τε κυρῶ: Ph. 1294. Cp. Tennyson's lines "To the Princess Frederica": “O you that were eyes and light to the King till he past away
From the darkness of life.
” Ant. 989 (of the blind Teiresias and his guide) “δὔ ἐξ ἑνὸς βλέποντε”.