Glasses, informally (5)
I believe the answer is:
specs
'glasses informally' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for specs that I've seen before include "Glasses (sl.)" , "Do they help one to see" , "Glasses (colloq.)" , "you can see right through them" , "provider of focus" .)