Synonyms to keen eye

eagle eye, X-ray eye, custodianship, custody, eye, gimlet eye, guard, guardedness, guardianship, invigilation, lookout, monitoring, observance, peeled eye, penetrating eye, proctoring, prudence, qui vive, scrutiny, sharp eye, stewardship, surveillance, tab, vigil, vigilance, wariness, watch, watch and ward, watchful eye, watchfulness, watching, weather eye, cover, defense, lee, preservation, protection, protective custody, refuge, safekeeping, safety, shade, shadow, shelter