Humans have poor night vision compared to many animals in part because the human eye lacks a tepetum lucidum. Moreover, only 10% of the light that enters the human eye falls on photosensitive parts of the retina. Large size of the eye, and large size of the pupil relative to the eye, also contributes to night vision.
Night vision is the ability to see in a dark environment. It is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range. A night vision device is a device comprising an IR image intensifier tube in a rigid causing. It is commonly used by military forces. Lately, night vision technology has become more widely available for civilian use. Some car manufacturers install portable vision cameras on their vehicles.
The thermal imaging are excellent tools for night vision. Contrary to other technologies, they do not need any light at all to produce a clear image. They make small temperature differences visible. They are widely used to compliment new or existing security networks.