Night vision glasses, used for seeing in the pitch dark night, use the little light available to form an image of sufficient brightness to be seen.
The image is first focussed, as in a camera, on to a window which is coated with special chemicals containing sodium, potassium, cadmium and oxygen compounds which emit electrons when illuminated.
The electrons so emitted are then accelerated by a series of powerful electric fields and made to fall onto another screen coated with a fluorescing chemical which glows recreating a much brighter image of the original scene.
Some night vision glasses make use of infrared radiation emitted by all objects even in the dark. These radiations are amplified in a similar way to make night vision possible.
