Scam on the rise captured in spy's single lens (7)
I believe the answer is:
monocle
'single lens' is the definition.
(a lens for one eye)
'scam on the rise captured in spy's' is the wordplay.
'scam' becomes 'con' (both can mean a fraudulent scheme).
'on the rise' is a reversal indicator (in a down clue, letters go up).
'captured in' is an insertion indicator.
'spy' becomes 'mole' (mole is a kind of spy).
'con' reversed gives 'noc'.
'noc' inserted inside 'mole' is 'MONOCLE'.
(Other definitions for monocle that I've seen before include "lens" , "optical device" , "Single eyeglass" , "One-lens seeing apparatus" , "Reading glass for one eye only" .)