Night vision aids allow people to observe objects in low-light situations and were developed during the Vietnam War.
There are two types of night vision aids:
1) Active Night Vision Aids shine an invisible infrared light on the object.  The person can then look through binoculars or a viewing scope that is sensitive to the infrared spectrum.  This type of night vision aid is effective up to 450 feet away from the object.  The only thing wrong with it is that the light must be shone in order to see the object, which can in turn be seen by others looking through an infrared viewer.  The price of an active aid is usually about $1,600.
2) Passive Night Vision Aids are sort of the opposite of active aids in that, instead of emitting light, it sucks in the light from the room.  No matter how pitch-dark it may be in a room, there is always SOME light, so it takes that light and uses a photomultiplier to boost the light 35,000 to 80,000 times, taking it up to visible levels.
    Monocular passive night vision aids use batteries and can detect people from 600 feet away for about $4,000.  Night vision goggles, however, can be strapped on without batteries for continuous night viewing for $7,000.  The night vision binoculars are about $10,000. (Yost 208)

Monocular Goggles          Night Vision Binoculars
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Night Scope:
picture borrowed from (The Spy Shop)
Built by a Russian optical company, this uses invisible infrared light to illuminate total darkness night vision.  ($350)
Voltage:  2.5-3V
Current:  100 mA
(Spy Shop)

This page was last updated May 12th at approxiamately 4:18 PM