Half sure woman has something in her eye (6)
I believe the answer is:
retina
'something in her eye' is the definition.
(part of the eye)
'half sure woman' is the wordplay.
'half' suggests halving the letters.
'woman' becomes 'tina' (Tina is a woman's name).
'sure' cut in half is 're'.
're'+'tina'='RETINA'
'has' is the link.
(Other definitions for retina that I've seen before include "something that helps conjure up image" , "Viewer's part" , "part of the water pump" , "Bad tear in part of the eye" , "Eye's membrane" .)