Very observant (5-4)
I believe the answer is:
eagle-eyed
'very observant' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eagle-eyed that I've seen before include "Keenly observant" , "Visually on the ball" , "(Of someone) keeping a close watch" , "Very perceptive" , "Sharp of vision like noble bird" .)