夜视镜〈专业名称为夜视仪〉是透过光学科技强化黑暗中光源的科技设备，通常用于军事用途。目前在民用安防上也有广泛的用途。

原理:类似电视机，另一头是增强目镜一端的光度。可以说是最简单的夜视仪。

特点:需要微弱但既成的光源，例如星光、月光、灯光、火光等，在全黑的环境无法使用。但因为原理简单和造价低廉，而且完全漆黑的夜晚不常见，即使有也可以用人为不起眼的弱光补救。故自六十年代起便在越战中为美军大量地使用，成为至今应用最广泛的夜视仪器。

原理：仪器向外发射红外光束，照射目标，并将目标反射的红外图像转化成为可见光图像，从而进行夜间观察，军事上主要用于夜间瞄准、驾驶车辆、侦察照相等。

A Night Vision Device (NVD) is an optoelectronic device that allows images to be produced in levels of light approaching total darkness. The image may be a conversion to visible light of both visible light and near-infrared, while by convention detection of thermal infrared is denoted thermal imaging. The image produced is typically monochrome, e.g. shades of green. NVDs are most often used by the military and law enforcement agencies, but are available to civilian users. The term usually refers to a complete unit, including an image intensifier tube, a protective and generally water-resistant housing, and some type of mounting system. Many NVDs also include optical components such as a sacrificial lens, or telescopic lenses or mirrors. An NVD may have an IR illuminator, making it an active as opposed to passive night vision device.