Night vision binoculars are based on these principles.
Infrared radiation and night vision Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves.
The name means "below red" (coming from the Latin word infra, which means "below"), red being the color of visible light with the longest wavelength.
Infrared radiation devices allow us to see in very low light levels, which human eyes call dark.
However, IR devices cannot help us see in total darkness: it has to be at least a faint level of light.
The military field makes use of IR night vision in lots of applications, such as: target acquisition, surveillance, homing and tracking.
Non-military also had a share of applications, such as thermal efficiency analysis, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
Infrared astronomy can detect cool objects such as planets, and to view highly red-shifted objects from the early days of the universe.
Either military or non military, the night vision binoculars make possible for us the sight of a world which was unknown until nowadays, the infrared world, with her gray-shaded beauty, which other animals perceive as normal.