The complete range of Helios monoculars
Monoculars, sometimes called telescopes when used in this capacity, are often used by visually impaired people to see distant objects that would normally be undiscernable. For example, they are often used to read text on a chalkboard or projection screen.
Besides their use by the visually impaired, they are also used in hunting, survival and espionage. For these specific tasks smaller monoculars are made that fit inside a regular pocket; they are frequently referred to as "pocket scopes". Companies producing them include Brunton, X20, Zeiss, Barska, ..