ðɪ ˌɑːɹpˌiːˈiː hɐz sˈɛvɹəl fˈʌŋkʃənz, nˈeɪmli, lˈaɪt ɐbsˈoːɹpʃən, ˌɛpɪθˈɛlɪəl tɹˈænspoːɹt, spˈeɪʃəl ˈaɪɑːn bˈʌfɚɹɪŋ, vˈɪʒuːəl sˈaɪkəl, fˌæɡəsɪtˈoʊsɪs, sᵻkɹˈiːʃən ænd ɪmjˈuːn mˌɑːdʒuːlˈeɪʃən.
The RPE has several functions, namely, light absorption, epithelial transport, spatial ion buffering, visual cycle, phagocytosis, secretion and immune modulation.