The light-capture area of a photoreceptor.
D000818:Animals; D001699:Biometry; D004175:Diptera; D006801:Humans; D008027:Light; D055095:Optics and Photonics; D010786:Photoreceptor Cells / Q000033:anatomy & histology* / Q000502:physiology; D014785:Vision, Ocular