Binoculars were devices used to look at things from a distance.
On Vortis, the First Doctor used binoculars to observe the Zarbi. (PROSE: The Lair of Zarbi Supremo) On Skaro, he used binoculars to survey the Dalek City. (TV: The Daleks) On Bruhl, he used binoculars to observe Grahm being pursued by the police. (PROSE: Justice of the Glacians)
On Venus, Jeff and Andy Stone used binoculars to observe an oil well under Dalek control. They later used the glass lenses in the binoculars to magnify heat directly onto the oil well, causing it to explode. (COMIC: The Oil Well)