Time to take a different position in the issue of sight (5)
I believe the answer is:
optic
'of sight' is the definition.
(I've seen this in another clue)
I cannot understand how the remainder of the clue works.
(Other definitions for optic that I've seen before include "Visual" , "Alcoholic drink dispenser" , "Pertaining to the eye" , "connected to the eye" , "bar assistant" .)