How Night Vision Devices Work: A Simple Guide

There are many types of night vision devices on the market. Let’s start by defining the difference between night goggles and night vision goggles.

Night vision goggles are optical devices that allow the operator to see images at different levels of light, approaching total darkness. Night glasses only amplify what is already available through purely optical means using only large diameter lenses. The most common types of night vision goggles include night binoculars (giant binoculars with a very large lens diameter) and telescopes, most likely used for astronomical purposes.

Night vision devices (NVGs) differ from night goggles in that they are not purely optical devices. These are electro-optical devices that consist of an IR image amplifier tube enclosed in a protective casing. NVG amplifies any existing light and sends it to the eyes. You don’t actually look directly through the NVG optics like you do with night glasses, you instead look at an amplified electronic image on a phosphor screen. Typically, NVGs include IR illuminators and telescopic lenses. Examples of these types of NVGs include monoculars, binoculars, scopes, or goggles. Night vision goggles are commonly used for nighttime wildlife viewing, night shooting and photography, and maritime navigation and security.

How does night vision work?
The whole process of Night Vision is complex, and many factors determine the final result. Simply put, night vision takes small electrical charges not detectable by the human senses and multiplies them to a perceptible level.

A night vision device collects the smallest particles of light and focuses them in an image intensifier. The image intensifier then converts the light particles into electrons. The electrons are then multiplied and projected onto a green phosphorescent screen. When the multiplied electrons hit the phosphor screen, it causes the screen to emit light that is visible to the naked eye.