Can it retain optical images? (6)
I believe the answer is:
retina
'can' is the definition.
The definition and answer can be both body parts as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'it retain optical images?' is the wordplay.
'retain' anagrams to 'RETINA'.
But, I am not clear how this is indicated.
Can you help me to learn more?
(Other definitions for retina that I've seen before include "Retain with part of eye" , "Eye's membrane" , "Membrane in eye, sensitive to light" , "part of the water pump" , "Where you focus" .)