Eye part with rods and cones (6)
I believe the answer is:
retina
'eye part with rods and cones' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for retina that I've seen before include "Bad tear in part of the eye" , "Light-sensitive membrane of the eyeball" , "Membrane that can become detached" , "Light-receptive part of eye" , "Eye's membrane" .)