Notices defects (5)
I believe the answer is:
spots
I believe this clue is a double definition.
'notices' is the first definition.
(spot can mean to notice or see)
'defects' is the second definition.
(spot is a kind of defect)
(Other definitions for spots that I've seen before include "Result of outbreak, possibly" , "Catches sight of" , "Sees" , "Picks out" , "Espies the blobs?" .)