Eeyore's poor sight (7)
I believe the answer is:
eyesore
'sight' is the definition.
(thesaurus)
'eeyore's poor' is the wordplay.
'poor' indicates anagramming the letters.
'eeyores' anagrammed gives 'EYESORE'.
(Other definitions for eyesore that I've seen before include "horror" , "Something that's ugly" , "Hideous sight" , "Ugly sight, not nice to see" , "Ugly item" .)