Light-sensitive eye lining (6)
I believe the answer is:
retina
'light-sensitive eye lining' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for retina that I've seen before include "It helps one to see" , "Light-sensitive eye lining" , "Bad tear in part of the eye" , "Eye's membrane" , "Tear in (anag) - part of the eye" .)