They help us to see tiny spots, we hear (5)
I believe the answer is:
specs
'they help us to see' is the definition.
'tiny spots we hear' is the wordplay.
'tiny spots' becomes 'specks' (I've seen this before).
'we hear' shows a homophone (sound like).
'specks' is a homophone of 'SPECS'.
(Other definitions for specs that I've seen before include "provider of focus" , "what builders are doing?" , "you can see right through them" , "Details for designer" , "Glasses (colloq.)" .)