Have a good look wearing half-glasses (7)
I believe the answer is:
inspect
'have a good look' is the definition.
'wearing half-glasses' is the wordplay.
'wearing' becomes 'in' (wear in (and 'in' is fashionable)).
'half' means to take half the letters.
'glasses' becomes 'spectacles' ('spectacles' can be a synonym of 'glasses').
'spectacles' cut in half is 'spect'.
'in'+'spect'='INSPECT'
(Other definitions for inspect that I've seen before include "Look critically at" , "Scrutinise" , "Go over" , "Look at closely" , "Scrutinize, audit" .)