Eye surgery to itch from time to time (5)
I believe the answer is:
optic
'eye' is the definition.
('optic' can be a synonym of 'eye')
'surgery to itch from time to time' is the wordplay.
'surgery' becomes 'op' (short for operation).
'from time to time' indicates alternate letters (letters removed on a regular basis).
'to'+'itch'='toitch'
The alternating letters of 'toitch' are 'tic'.
'op'+'tic'='OPTIC'
(Other definitions for optic that I've seen before include "Publican's measuring device" , "Pertaining to sight" , "Topic (anag.)" , "Relating to vision" , "Spirits dispenser" .)