Operation on twitch related to the eye (5)
I believe the answer is:
optic
'eye' is the definition.
(synonyms)
'operation on twitch' is the wordplay.
'operation' becomes 'op'.
'on' says to put letters next to each other.
'twitch' becomes 'tic' (tic is a kind of twitch).
'op'+'tic'='OPTIC'
'related to the' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for optic that I've seen before include "Teacher's maybe coming through this" , "Of sight or the eye" , "Like a sort of nerve" , "Pub drinks dispenser" , "Relating to the eyes" .)