Choose strange CIA novice in sight (7)
I believe the answer is:
optical
'in sight' is the definition.
(optical means relating to sight)
'choose strange cia novice' is the wordplay.
'choose' becomes 'opt' (both can mean to pick something).
'strange' indicates anagramming the letters.
'novice' becomes 'L' (as in a learner driver with L-plates on their car).
'cia' with letters rearranged gives 'ica'.
'opt'+'ica'+'l'='OPTICAL'
(Other definitions for optical that I've seen before include "Coal tip (anag)" , "Involving light" , "Relating to sight" , "Relating to light/vision" , "some kind of illusion" .)