Spectacles not usually seen at night (10)
I believe the answer is:
sunglasses
'spectacles' is the definition.
(sunglasses is a kind of spectacles)
'not usually seen at night' is the wordplay.
I cannot really see how this works, but
'not' could be 'un' (prefix meaning 'not') and 'un' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sunglasses that I've seen before include "viewing aids" , "Tracey Ullman hit" , "protection for pupils" , "These offer a sight more protection" , "summer wear" .)