Blight that I spotted, say (7)
I believe the answer is:
eyesore
'blight' is the definition.
(I've seen this before)
'i spotted say' is the wordplay.
'i' becomes 'eye' (I've seen this in other clues).
'spotted' becomes 'saw' (I've seen this before).
'say' indicates a 'sounds like' (homophone) clue.
'saw' is a homophone of 'sore'.
'eye'+'sore'='EYESORE'
'that' acts as a link.
(Other definitions for eyesore that I've seen before include "Ugly object, hard on the sight" , "pigsty" , "Something ugly to look at" , "mess" , "terrible prospect" .)