Eye work that gets a lot of credit (5)
I believe the answer is:
Here is my best explanation:
'eye' is the definition.
('optic' can be a synonym of 'eye')
'work that gets a lot of credit' is the subsidiary indication.
'work' becomes 'op' (common abbreviation for 'opus'**).
'that gets' is a charade indicator (letters next to each other).
'a lot of' means to remove the last letter.
'credit' becomes 'tick' (I've seen this in other clues).
'tick' with its last letter removed is 'tic'.
(Other definitions for optic that I've seen before include "affecting vision?", "The nerve", "Topic (anag.)", "Relating to sight", "Of sight or the eye", "Device for dispensing measures of spirits", "Relating to vision", "Pertaining to sight", "Drinks dispenser" and "Nerve".)