What does the night vision function actually consist of? This optical device is designed not only to focus the light, but also to enhance it. This is the most important feature that distinguishes night vision from binoculars or rifle scopes.
A night vision lamp or an image intensifier, which is additionally equipped with a night vision device, allows for electric light amplification. This is the most important part of this device, thanks to which the light focused by the night vision lens can be converted into a stream of electrons that are accelerated in the electromagnetic field. When they collide with a screen that is covered with phosphorus, the image of the environment in darkness is reproduced on it. Thanks to this, through the night vision glasses we can see the surroundings very clearly, even at night.
Each of us knows perfectly well from experience that at night we are not able to see too much. This is because our body is adapted to function during the day, so after dark we see very badly. Unlike many animals, especially predators, which lead a night lifestyle, our eyesight is not distinguished by its sensitivity in such conditions. Therefore, in order to help each other a little, specialists worked on a system that will allow us to see better also in the dark. Thus, in the 1920s, night vision was born.
No matter where we are, in most cases we can count on a lot of light, be it from the moon and stars, or from places where people live. Even hardly noticeable light of this kind can be ideal for night vision. A good device can use such partial light and amplify it up to 35 thousand times. Thanks to this, if the area is exposed, we can see everything up to the horizon. What's more, during a full moon, the image visible through the night vision device looks almost as if we were watching it on a sunny day. Devices that also provide high magnification, from 1 to 5 times, also allow you to see the silhouette of a human or animal, from 700 meters.
However, if there is no partial light in the area where we are, we have to use an illuminator. Each device of this type has an infrared illuminator, which is also often called a laser, diode or backlight. It works like a flashlight that we use in the dark. So when we are surrounded by total darkness, we can turn on the illuminator in the night vision, which usually allows us to see the surrounding area at a distance of 50-200 meters. If the night vision device is able to catch any partial light, this range is increased immediately.