Synonyms for Argus-eyed (same or very similar meaning)
WordNet sense 1 (having very keen vision):
hawk-eyed, lynx-eyed, sharp-eyed, keen-sighted, quick-sighted, sharp-sightedWordNet sense 2 (able to see):
sightedWordNet sense 3 (carefully observant or attentive; on the lookout for possible danger):
open-eyed, vigilant, wakefulWordNet sense 4 (very attentive or observant):
alertFrom the ODE community, based on WordNetadd/edit