Is ἔμπροσθεν καὶ ὄπισθεν referring to the animals' positions in relation to the throne (from where John is looking), or to the position of their eyes on their bodies (relative to their own orientation to the throne).Revelations 4:6 wrote:καὶ ἐνώπιον τοῦ θρόνου ὡς θάλασσα ὑαλίνη, ὁμοία κρυστάλλῳ. Καὶ ἐν μέσῳ τοῦ θρόνου καὶ κύκλῳ τοῦ θρόνου τέσσαρα ζῷα γέμοντα ὀφθαλμῶν ἔμπροσθεν (facing the throne / closer to John) καὶ ὄπισθεν (looking away from the throne [cf. Rev. 5:1 obverse - reverse of a scroll in NA-UBS text] / further from the narrator's stand-point).
Another point: I guess that ἐν μέσῳ τοῦ θρόνου means centred around the throne. [With the adverb's reference point ("looking") from the inside out, rather than from the outside in.]