Part of the eye may be near it (6)
I believe the answer is:
retina
'part of the eye' is the definition.
(I know that retina is part of eye)
'may be near it' is the wordplay.
'may be' is an anagram indicator.
'near'+'it'='nearit'
'nearit' anagrammed gives 'RETINA'.
(Other definitions for retina that I've seen before include "Sensitive part of eye" , "Membrane covering the back of the eyeball" , "Light-sensitive membrane in the eye" , "Light-sensitive eye lining" , "Sensitive layer in eye" .)