The idea of a "mind's eye" goes back at least to Cicero's reference to mentis oculi during his discussion of the orator's appropriate use of simile.
ðɪ aɪdˈiə əvə "mˈaɪndz ˈaɪ" ɡoʊz bˈæk æt lˈiːst tə sˈaɪsɹoʊz ɹˈɛfɹəns tə mˈɛntiz ˈɑːkjʊlˌaɪ dˈʊɹɹɪŋ hɪz dɪskˈʌʃən ʌvðɪ ˈɔːɹəɾɚz ɐpɹˈoʊpɹɪət jˈuːs ʌv sˈɪmɪli.