A night-vision device (NVD), also known as a night optical/observation device (NOD) or night-vision goggle (NVG), is an optoelectronic device that allows visualization of images in low levels of light, improving the user's night vision. The device enhances ambient visible light and converts near-infrared light into visible light which can then be seen by humans; this is known as I2 (image intensification). By comparison, viewing of infrared thermal radiation is referred to as thermal imaging and operates in a different section of the infrared spectrum. A night vision device usually consists of an image intensifier tube, a protective housing, and an optional mounting system. Many NVDs also include a protective sacrificial lens, mounted over the front/objective lens to prevent damage by environmental hazards, while some incorporate telescopic lenses. An NVD image is typically monochrome green, as green was considered to be the easiest color to see for prolonged periods in the dark. Night vision devices may be passive, relying solely on ambient light, or may be active, using an IR (infrared) illuminator. Night vision devices may be handheld or attach to helmets. When used with firearms, an IR laser sight is often mounted to the weapon. The laser sight produces an infrared beam that is visible only through an NVD and aids with aiming. Some night vision devices are made to be mounted to firearms. These can be used in conjunction with weapon sights or standalone; some thermal weapon sights have been designed to provide similar capabilities. These devices were first used for night combat in World War II and came into wide use during the Vietnam War. The technology has evolved since then, involving "generations" of night-vision equipment with performance increases and price reductions. Consequently, though they are commonly used by military and law enforcement agencies, night vision devices are available to civilian users for applications including aviation, driving, and demining. The global market for night-vision devices was valued at approximately US$7.5 billion in 2024 and is projected to reach US$9.5 billion by 2030.
History
In 1929 Hungarian physicist Kálmán Tihanyi invented an infrared-sensitive electronic television camera for anti-aircraft defense in the UK. Night vision technology prior to the end of World War II was later described as Generation 0. Night-vision devices were introduced in the German Army as early as 1939 and were used in World War II. AEG started developing its first devices in 1935. In mid-1943, the German Army began testing infrared night-vision devices and telescopic rangefinders mounted on Panther tanks. Two arrangements were constructed. The Sperber FG 1250 ("Sparrow Hawk"), with a range of up to 600 metres (2,000 ft), had a 30-centimetre (12 in) infrared searchlight and an image converter operated by the tank commander. From late 1944 to March 1945 the German military conducted successful tests of FG 1250 sets mounted on Panther Ausf. G tanks (and other variants). During the war, approximately 50 (or 63) Panthers were equipped with the FG 1250 and saw combat on both the Eastern and Western Fronts. The "Vampir" man-portable system for infantry was used with StG 44 assault rifles. Parallel development occurred in the US. The M1 and M3 infrared night-sighting devices, also known as the "sniperscope" or "snooperscope", saw limited service with the US Army in World War II and in the Korean War, to assist snipers. These were active devices, using an infrared light source to illuminate targets. Their image-intensifier tubes used an anode and an S-1 photocathode, made primarily of silver, cesium, and oxygen, the image was inverted electrostatically and electron acceleration produced gain. An experimental Soviet device called the PAU-2 was field-tested in 1942. In 1938 the British Admiralty assumed responsibility for British military infra-red research. They worked with Philips until the fall of the Netherlands, then with Philips' UK subsidiary Radio Transmission Equipment Ltd., and finally with EMI, who in early 1941 provided compact, lightweight image converter tubes. By July 1942 the British had produced a binocular apparatus called 'Design E'. This was bulky, needing an external power pack generating 7,000 volts, but saw limited use with amphibious vehicles of 79th Armoured Division in the 1945 crossing of the Rhine. Between May and June 1943, 43rd (Wessex) Infantry Division trialled man-portable night vision sets, and the British later experimented with mounting the devices to Mark III and Mark II(S) Sten submachine guns. However, by January 1945 the British had only made seven infra-red receiver sets. Although some were sent to India and Australia for trials before the end of 1945, by the Korean War and Malayan Emergency the British were using night vision equipment supplied by the United States. Early examples include:
FG 1250 Sperber ZG 1229 Vampir PAU-2 PNV-57A tanker goggles SU-49/PAS-5 T-120 Sniperscope, 1st model (World War II) M2 Sniperscope, 2nd model (World War II) M3 Sniperscope, 4th model (Korean War) AN/PAS-4 (early Vietnam War) After World War II, Vladimir K. Zworykin developed the first practical commercial night-vision device at Radio Corporation of America, intended for civilian use. Zworykin's idea came from a former radio-guided missile. At that time, infrared was commonly called black light, a term later restricted to ultraviolet. Zworykin's invention was not a success due to its large size and high cost.
United States
Generation 1
First-generation passive devices developed by the US Army in the 1960s were introduced during the Vietnam War. They were an adaptation of earlier active technology and relied on ambient light instead of using an extra infrared light source. Using an S-20 photocathode, their image intensifiers amplified light around 1,000-fold, but they were quite bulky and required moonlight to function properly. Examples:
AN/PVS-1 Starlight scope AN/PVS-2 Starlight scope AN/PAS-6 Varo Metascope
Generation 2
1970s second-generation devices featured an improved image-intensifier tube using a micro-channel plate (MCP) with an S-25 photocathode. This produced a much brighter image, especially around the edges of the lens. This led to increased clarity in low ambient-light environments, such as moonless nights. Light amplification was around 20,000. Image resolution and reliability improved. Examples:
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