I refer to sound and vision (8)
I believe the answer is:
eyesight
'vision' is the definition.
(eyesight is a kind of vision)
'i refer to sound' is the wordplay.
'i' becomes 'eye' (I've seen this in other clues).
'refer to' becomes 'cite' (synonyms).
'sound' shows a homophone (sound like).
'cite' sounds like 'sight'.
'eye'+'sight'='EYESIGHT'
'and' is the link.
(Other definitions for eyesight that I've seen before include "Faculty of vision" , "Seeing ability" , "quality of viewing" , "View" , "Showing sense" .)