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"as defined by the US Army Night Vision and Electronic Sensors Directorate (NVESD) 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 , had a 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.Biographical sketch 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 -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 . Image resolution and reliability improved.
Examples: AN/PVS-3 Miniaturized night vision sight AN/PVS-4 AN/PVS-5 SUPERGEN
Later advances brought GEN II+ devices (equipped with better optics, SUPERGEN tubes, improved resolution and better signal-to-noise ratios), though the label is not formally recognized by the NVESD.
Generation 3
Third-generation night-vision systems, developed in the late 1980s, maintained the MCP from Gen II, but used a gallium arsenide (GaAs) photocathode, with improved resolution. GaAs photocathodes are primarily manufactured by L3Harris Technologies and Elbit Systems of America and imaged light from (blue-green to near infrared). In addition, the MCP was coated with an ion barrier film to increase tube life. However, the ion barrier allowed fewer electrons to pass through. The ion barrier increased the "halo" effect around bright spots or light sources. Because of those negative effects the ion barriers on newer tubes were made significantly thinner. Light amplification (and power consumption) with these devices improved to around .
Examples: AN/PVS-7 AN/NVS-7 AN/PVS-10 AN/PVS-14 AN/PVS-17 CNVS-4949 PN-21K AGM UNVG-RPO
Auto-gating Autogating (ATG) rapidly switches the power supply's voltage to the photocathode on and off. These switches are rapid enough that they are not detectable to the human eye and peak voltage supplied to the night vision device is maintained. This reduces the "duty cycle" (ie. the amount of time that the tube has power running through it) in high light conditions which increases the device's lifespan and lets it maintain resolution better. Autogating also enhances the Bright-Source Protection (BSP), which reduces the voltage supplied to the photocathode in response to ambient light levels. Automatic Brightness Control (ABC) modulates the amount of voltage supplied to the microchannel plate (rather than the photocathode) in response to ambient light. Together, BSP and ABC (alongside autogating) serves to prevent damage to the tube when the night vision device is exposed to sudden bright sources of light, like a muzzle flash or artificial lighting. These modulation systems also help maintain a steady illumination level in the user's view that improves the ability to keep "eyes on target" in spite of temporary light flashes. These functions are especially useful for pilots, soldiers in urban environments, and special operations forces who may be exposed to rapidly changing light levels.
Generation 3+
OMNI, or OMNIBUS, refers to a series of contracts through which the US Army purchased GEN III night vision devices. This started with OMNI I, which procured AN/PVS-7A and AN/PVS-7B devices, then continued with OMNI II (1990), OMNI III (1992), OMNI IV (1996), OMNI V (1998), OMNI VI (2002), OMNI VII (2005), OMNI VIII, and OMNI IX. In April 2024, the US Army awarded L3Harris a $263 million production order for the ENVG-B under a program of record expected to total nearly $1 billion over ten years, and in December 2025 L3Harris and Palantir announced a partnership applying data analytics to improve night-vision production.
However, OMNI is not a specification. The performance of a particular device generally depends upon the tube which is used. For example, a GEN III OMNI III MX-10160A/AVS-6 tube performs similarly to a GEN III OMNI VII MX-10160A/AVS-6 tube, even though the former was manufactured in ~1992 and the latter ~2005.
One particular technology, PINNACLE is a proprietary thin-film microchannel plate technology created by ITT that was included in the OMNI VII contract. The thin-film improves performance.
GEN III OMNI V–IX devices developed in the 2000s and onward can differ from earlier devices in important ways:
An automatic gated power supply system regulates the photocathode voltage, allowing the NVD to instantaneously adapt to changing light conditions. A removed or greatly thinned ion barrier that decreases the number of electrons that are rejected by GEN III MCP, hence resulting in less image noise. The disadvantage to a thin or removed ion barrier is the overall decrease in tube life from a theoretical mean time to failure (MTTF) for standard Gen III type, to MTTF for thin film types. This loss is largely negated by the low number of image-intensifier tubes that reach of operation before requiring replacement.
The consumer market sometimes classifies such systems as Generation 4, and the United States military describes these systems as Generation 3 autogated tubes (GEN III OMNI V-IX). Moreover, as autogating power supplies can be added to any previous generation of night-vision devices, autogating capability does not automatically put the devices in a particular OMNI classification. Any postnominals appearing after a generation type (i.e., Gen II+, Gen III+) indicate improvement(s) over the original specification's requirements.
Examples: AN/PVS-14 AN/PVS-22 NVS-22 Binocular Night Vision Device (BNVD) (AN/PVS-15, AN/PVS-21, AN/PVS-23, AN/PVS-31A/D) Ground Panoramic Night Vision Goggle (GPNVG-18)
Figure of merit Figure of merit (FoM) is a rough quantitative Figure of a NVD's effectiveness and clarity. It is calculated using the number of line pairs per millimeter that a user can detect multiplied by the image intensifier's signal-to-noise ratio (SNR).
In the late 1990s, innovations in photocathode, power supply and microchannel plate (MCP) technology significantly increased the SNR.