Crossword Genius

Disheartened envoy for one misses visual aids (10)

Ross

I believe the answer is:

eyeglasses

'visual aids' is the definition.
(eyeglasses help people to see)

'disheartened envoy for one misses' is the wordplay.
'disheartened' suggests removing the centre.
'for one' becomes 'eg' (both can mean 'for example').
'misses' becomes 'lasses' (lass is a kind of miss).
'envoy' with its middle removed is 'ey'.
'ey'+'eg'+'lasses'='EYEGLASSES'

I've seen this clue in The Guardian.
Want a hint initially instead of a full solution? Install my app