This technology was introduced to provide benefit to the people who cannot see at night. This technology actually allows one to see in the dark. It was basically developed for the military purpose as humans have poor night vision when compared to animals. With the proper night-vision equipment, we can see a person standing 200 yards away on a moonless, cloudy night.
There are two types of night vision:
1) Biological Night Vision: here molecules in the rods of the eye undergo a change in shape as light as molecules in the human rod are insensitive to the light.
2) Technical Night Vision: it is an image intensifier. It supports thermal imaging.
Now let us discuss the working of technical night vision.
• Image Intensifier: Firstly, night vision amplifies light to get better vision. Now, the gathered light the conventional lens is sent to image intensifier tube. The light energy releases an electron from the cathode and accelerate. These electrons now enter into microchannel plate and from there they bounce off and generate more electrons. This is how thousands of other electrons release in each channel. Here original electrons collide with the channel, which excites atoms and cause other electrons and now new electrons collide with other atoms and this is how chain continues.
• Thermal Imaging: A lens focuses the infrared light this light is scanned and this creates a temperature pattern. Now the generated pattern is translated into electric impulses then are sent to a circuit board which translates it into data for the display. Thermal images are black and white in nature.
Various Night Vision Devices are:
• Scopes: they are monocular
• Goggles: they are binocular
• Cameras: used for transmission or recording of images
They are used in the field of military, hunting, security, wildlife observation and hidden object detection. In the present scenario, the applications of night vision technology play a very essential part in our day to day life.