Crossword Genius

Part of the eye that’s concerning can start to atrophy (6)

Ross

I believe the answer is:

(Other definitions for retina that I've seen before include "Sensitive part of eye", "Where you focus", "something that helps conjure up image", "Tear in (anag) - part of the eye", "Light-sensitive membrane of the eyeball".)

I've seen this clue in The Times.