Binoculars

Binoculars were a device used by Humans and other species. They had small identical mirrors inside them, which allowed a person to view distant objects with both eyes. James T. Kirk and Spock used 23rd century versions of binoculars while on Nimbus III after landing far from Paradise City. Earlier, Leonard McCoy used the same binoculars to view Kirk climbing El Capitan. 

Geordi La Forge's VISOR functioned much like binoculars in some cases. 

In 2375, Captain Jean-Luc Picard viewed the mountains on Ba'ku through binoculars with Anij while looking for suitable locations to hide from the Son'a.