Audibly agreed with doctor before operations which may improve one's sight (3,5)

'which may improve one's sight' is the definition.

'audibly agreed with doctor before operations' is the wordplay.
'audibly' shows a homophone (sound like).
'agreed' becomes 'aye'.
'with' is a charade indicator (letters next to each other).
'doctor before' becomes 'dr' ('Dr' can be a synonym of 'doctor'. I am not sure about the 'before' bit.**).
'operations' becomes 'ops' (I have seen 'Military operations ' mean 'ops' so perhaps 'operations' could also mean 'ops').
'aye' sounds like 'eye'.
'eye'+'dr'+'ops'='EYE-DROPS'