The Binoculars have been a part of Lara's gear in The Last Revelation, Tomb Raider Chronicles and Tomb Raider Legend. In Lara Croft: Relic Run the binoculars are a kind of Clue.
The Last Revelation
As the Binoculars became a new addition to Lara's gear, it's possible to see details from a greater distance. This might help to spot important elements of puzzles, or simply aid in where to go next.
Tomb Raider Chronicles
In addition to the features introduced in the usage of Binoculars The Last Revelation, there's a Headset, which works much like the Binoculars, in the VCI Section. When using the Headset Lara is able to see otherwise invisible lasers.
Tomb Raider Legend
State of the art binoculars with included R.A.D. technology allows for Remote Analysis and Display of object characteristics from up to 1200m away. 
Press the binocular key to activate the binoculars and the interaction key for R.A.D mode. All objects that are either explosive, movable, part of a mechanism or fragile will be highlighted.
Lara Croft: Relic Run
Binoculars can be collected like the other Clues and will help Lara on her search for Relics.
- ↑ Tomb Raider Legend, in-game information from PDA