How Does Night-Vision Technology Work?

There are two main approaches. Image-intensifier (I²) night vision collects tiny amounts of ambient light (starlight, moonlight) through an objective lens. Photons strike a photocathode, releasing electrons that are multiplied thousands of times by a micro-channel plate (MCP) — a thin glass disc with millions of tiny channels. The amplified electrons hit a phosphor screen, producing the characteristic green image (green chosen because the human eye can distinguish more shades of green). Thermal imaging, the second approach, detects infrared radiation emitted by all objects above absolute zero, creating a heat map. Modern military systems combine both for maximum effectiveness.