the element in a camera is anyway transferred from the anatomical region that surrounds the pupil in the eye, so-called (since 1525 via SOED) bcz it is rainbow coloured, iris being the greek goddess of the rainbow -- and "irised" did actually pre-exist (acc.SOED, i've never spotted it) as a poetic verb meaning "exhibited the characteristics of a rainbow"
so there's a quadruple meaning transference, which is fun: from name-of-a-god to colour quality to mechanism (purposive-muscular) to mechanism (purposive-mechanical) to mechanism (similar mechanism different purpose)
― mark s, Monday, 30 December 2019 17:01 (four years ago) link