keen eye - Wordage.info - Free Thesaurus Tool for Word Discovery - Expanded Thesaurus, Reverse Dictionary Lookup

monitoring collapse: the act of observing something (and sometimes keeping a record of it); "the monitoring of enemy communications plays an important role in war times"

horizon collapse: the range of interest or activity that can be anticipated; "It is beyond the horizon of present knowledge"; the line at which the sky and Earth appear to meet; the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth; a specific layer or stratum of soil or subsoil in a vertical cross section of land

surveillance collapse: close observation of a person or group (usually by the police)

retina collapse: the light-sensitive membrane covering the back wall of the eyeball; it is continuous with the optic nerve

lens collapse: a transparent optical device used to converge or diverge transmitted light and to form images; electronic equipment that uses a magnetic or electric field in order to focus a beam of electrons; biconvex transparent body situated behind the iris in the eye; it focuses light waves on the retina; (metaphor) a channel through which something can be seen or understood; "the writer is the lens through which history can be seen"; genus of small erect or climbing herbs with pinnate leaves and small inconspicuous white flowers and small flattened pods: lentils

squint collapse: the act of squinting; looking with the eyes partly closed; cross one's eyes as if in strabismus; "The children squinted so as to scare each other"; partly close one's eyes, as when hit by direct blinding light; "The driver squinted as the sun hit his windshield"; be cross-eyed; have a squint or strabismus