It could give you a better view of French city (4)

I believe the answer is:

lens

I'm a little stuck... Click here to teach me more about this clue!

'french city' is the definition.
(Lens is a French city)

I don't understand how the remainder of the clue works.

(Other definitions for lens that I've seen before include "Refracting device" , "Transparent optical device" , "Through which to view" , "Optical refractor" , "Aid for viewing" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app