Spots, we hear, for glasses (5)
I believe the answer is:
specs
'for glasses' is the definition.
(spectacles)
'spots we hear' is the wordplay.
'spots' becomes 'specks' (I've seen this before).
'we hear' shows a homophone (sound like).
'specks' sounds like 'SPECS'.
(Other definitions for specs that I've seen before include "provider of focus" , "what builders are doing?" , "Do they help one to see" , "Glasses (colloq.)" , "Details for designer" .)