There are basically 3 options for night vision:

1.The possibility of digital image amplification using so-called CCD/CMOS sensors. Whereby the processor processing results in a delayed display of the output image.

2.The possibility of amplifying weak residual or infrared light (NIR) through an image intensifier tube (IIT's).

3.And the ability to see heat signatures. In this way, the infrared radiation in the MWIR / LWIR range is recorded and converted into an image, that allowes you to see temperature differences in the environment.

On this page it is primarily about the "classic" night vision devices with image intensifier tubes (IIT's), so let's go on...