quester, searcher, seeker - someone making a search or inquiry; "they are seekers after truth"

beholder, observer, perceiver - a person who becomes aware (of things or events) through the senses

camera, photographic camera - equipment for taking photographs (usually consisting of a lightproof box with a lens at one end and light-sensitive film at the other)

gun-sight, gunsight - a sight used for aiming a gun

optical device - a device for producing or controlling light

telescope, scope - a magnifier of images of distant objects