Definitions for eagle-eyed
Random House Webster's College Dictionary
unusually sharp visual powers; keen ability to watch or observe.
a person who has sharp vision or maintains a keen watchfulness.
Origin of eagle eye:
eagle-eyed, keen-sighted, farseeing, longsighted(adj)
capable of seeing to a great distance
Having great visual acuity, especially the ability to see at a distance.
describing someone who is perceptive.
sharp-sighted as an eagle