A rear-view mirror (or rearview mirror) is a flat mirror in

automobile A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods. The year 1886 is regarde ...

s and other vehicles, designed to allow the driver to see rearward through the vehicle's rear window (rear

windshield The windshield (North American English) or windscreen (Commonwealth English) of an aircraft, car, bus, motorbike, truck, train, boat or streetcar is the front window, which provides visibility while protecting occupants from the elements. ...

). In cars, the rear-view mirror is usually affixed to the top of the

on a double-

swivel A swivel is a connection that allows the connected object, such as a gun, chair, swivel caster, or an anchor An anchor is a device, normally made of metal , used to secure a vessel to the bed of a body of water to prevent the craft ...

mount allowing it to be adjusted to suit the height and viewing angle of any driver and to swing harmlessly out of the way if impacted by a vehicle occupant in a

collision In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great fo ...

. The rear-view mirror is augmented by one or more side-view mirrors, which serve as the only rear-vision mirrors on

trucks A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...

motorcycle A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruising ...

s and bicycles.

History

Among the rear-view mirror's early uses is a mention by

Dorothy Levitt Dorothy Elizabeth Levitt (born Elizabeth Levi; 5 January 1882 – 17 May 1922) was a British racing driver and journalist. She was the first British woman racing driver, holder of the world's first water speed record, the women's world lan ...

in her 1909 book ''The Woman and the Car'' which noted that women should "carry a little hand-mirror in a convenient place when driving" so they may "hold the mirror aloft from time to time in order to see behind while driving in traffic". However, earlier use is described in 1906, in a trade magazine noting mirrors for showing what is coming behind now popular on closed bodied automobiles, and to likely be widely adopted in a short time. The same year, a Mr. Henri Cain from

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

patented a "''Warning mirror for automobiles''". The Argus Dash Mirror, adjustable to any position to see the road behind, appeared in 1908. Earliest known rear-view mirror mounted on a racing vehicle appeared on

Ray Harroun Ray Harroun (January 12, 1879 – January 19, 1968) was an American racecar driver and pioneering constructor most famous for winning the inaugural Indianapolis 500 in 1911. He is the inventer of the open-wheel car. Biography He was born on Janua ...

's Marmon race car at the inaugural

Indianapolis 500 The Indianapolis 500, formally known as the Indianapolis 500-Mile Race, and commonly called the Indy 500, is an annual automobile race held at Indianapolis Motor Speedway (IMS) in Speedway, Indiana, United States, an enclave suburb of Indi ...

race in 1911. Harroun himself claimed he got the idea from seeing a mirror used for a similar purpose on a horse-drawn vehicle in 1904. Harroun also claimed that the mirror vibrated constantly due to the rough brick surface, and it was rendered largely useless. Elmer Berger is usually credited with inventing the rear-view mirror, though in fact he was the first to patent it (1921) and develop it for incorporation into production street going automobiles by his Berger and Company.

Augmentations and alternatives

Recently, rear-view video cameras have been built into many new model cars, this was partially in response to the rear-view mirrors' inability to show the road directly behind the car, due to the rear deck or trunk obscuring as much as 3–5 meters (10–15 feet) of road behind the car. As many as 50 small children are killed by

SUV A sport utility vehicle (SUV) is a car classification that combines elements of road-going passenger cars with features from off-road vehicles, such as raised ground clearance and four-wheel drive. There is no commonly agreed-upon definiti ...

s every year in the USA because the driver cannot see them in their rear-view mirrors. Camera systems are usually mounted to the rear bumper or lower parts of the car, allowing for better rear visibility. Aftermarket secondary rear-view mirrors are available. They attach to the main rear-view mirror and are independently adjustable to view the back seat. This is useful to enable adults to monitor children in the back seat.

Anti-glare

Memphis in Front of Me, Arkansas in Back of Me

prismatic An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are ''not'' prisms. The most familiar type of optical ...

rear-view

mirror A mirror or looking glass is an object that reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the im ...

—sometimes called a "day/night mirror"—can be tilted to reduce the brightness and glare of lights, mostly for high-beam

headlight A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in the most precise usage, ''headlamp'' is the term for the device itself and ''headlight'' is the term for ...

s of vehicles behind which would otherwise be reflected directly into the driver's eyes at night. This type of mirror is made of a piece of glass that is wedge-shaped in cross-section—its front and rear surfaces are not parallel. On manual tilt versions, a tab is used to adjust the mirror between "day" and "night" positions. In the day view position, the front surface is tilted and the reflective back side gives a strong reflection. When the mirror is moved to the night view position, its reflecting rear surface is tilted out of line with the driver's view. This view is actually a reflection of the low-reflection front surface; only a much-reduced amount of light is reflected in the driver's eyes. "Manual tilt" day/night mirrors first began appearing in the 1930s and became standard equipment on most passenger cars and trucks by the early 1970s.

Automatic dimming

In the 1940s, American inventor

Jacob Rabinow Jacob Rabinow (January 8, 1910 – September 11, 1999) was an engineer and inventor. He earned a total of 229 U.S. patents on a variety of mechanical, optical and electrical devices. Biography Rabinow was born in Kharkiv, Ukraine, on January 8, 1 ...

developed a light-sensitive automatic mechanism for the wedge-type day/night mirror. Several Chrysler Corporation cars offered these automatic mirrors as optional equipment as early as 1959, but few customers ordered them for their cars and the item was soon withdrawn from the option lists. Several automakers began offering rear-view mirrors with automatic dimming again in 1983, and it was in the late 1980s that they began to catch on in popularity. Current systems usually use

photosensor Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by ...

s mounted in the rear-view mirror to detect light and dim the mirror by means of

electrochromism Electrochromism is a phenomenon in which a material displays changes in color or opacity in response to an electrical stimulus. In this way, a smart window made of an electrochromic material can block specific wavelengths of ultraviolet, vis ...

. This electrochromic feature has also been incorporated into side-view mirrors allowing them to dim and reduce glare as well.

Suspending objects

Objects are sometimes hung from the rear-view mirror, including

cross necklace __NOTOC__ A cross necklace is any necklace featuring a Christian cross or crucifix. Crosses are often worn as an indication of commitment to the Christian faith, and are sometimes received as gifts for rites such as baptism and confirmation. Co ...

prayer beads Prayer beads are a form of beadwork used to count the repetitions of prayers, chants, or mantras by members of various religions such as Hinduism, Buddhism, Shinto, Umbanda, Islam, Sikhism, the Baháʼí Faith, and some Christian denominati ...

good luck charm In most contexts, the concept of good denotes the conduct that should be preferred when posed with a choice between possible actions. Good is generally considered to be the opposite of evil and is of interest in the study of ethics, morality, ph ...

s, decorations like

fuzzy dice Fuzzy dice, also known as fluffy dice, soft dice, or stuffed dice, are an automotive decoration consisting of two oversized (usually six-sided) plush dice which hang from the rear-view mirror. The original fuzzy dice, first used in the 1950s, we ...

, and air fresheners like

Little Trees Little Trees are disposable air fresheners shaped like a stylized evergreen tree, marketed for use in motor vehicles, and most commonly seen hanging from rear-view mirrors. They are made of a specially formulated absorbent material produced in a ...

. In some jurisdictions such hanging is illegal on the basis that it impairs the driver's forward view and so compromises safety.

Black Lives Matter Black Lives Matter (abbreviated BLM) is a decentralized political and social movement that seeks to highlight racism, discrimination, and racial inequality experienced by black people. Its primary concerns are incidents of police br ...

protesters have cited this as an example of the minor violations used as grounds for traffic stops disproportionately targeting black drivers.

Trucks and buses

On trucks and buses, the load often blocks rearward vision out the backlight. In the U.S. virtually all trucks and buses have a side view mirror on each side, often mounted on the doors and viewed out the side windows, which are used for rear vision. These mirrors leave a large unviewable ("blind") area behind the vehicle, which tapers down as the distance increases. This is a safety issue which the driver must compensate for, often with a person guiding the truck back in congested areas, or by backing in a curve. "Spot mirrors", a convex mirror which provides a distorted image of the entire side of the vehicle, are commonly mounted on at least the right side of a vehicle. In the U.S. mirrors are considered "safety equipment", and are not included in width restrictions.

Motorcycles

Depending on the type of motorcycle, the motorcycle may or may not have rear-view mirrors. Street-legal motorcycles are generally required to have rear-view mirrors. Motorcycles for off-road use only normally do not have rear-view mirrors. Rear-view mirrors come in various shapes and designs and have various methods of mounting the mirrors to the motorcycle, most commonly to the handlebars. Rear-view mirrors can also be attached to the rider's

motorcycle helmet A motorcycle helmet is a type of helmet used by motorcycle riders. Motorcycle helmets contribute to motorcycle safety by protecting the rider's head in the event of an impact. They reduce the risk of head injury by 69% and the risk of death by 42% ...

Bicycles

Some bicycles are equipped with a rear-view mirror mounted on a handlebar. Rear-view mirrors may also be fitted to the

bicycle frame A bicycle frame is the main component of a bicycle, onto which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles: a main triangl ...

, on a

helmet A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman's helmet in the United Kingdom) without protect ...

on the

arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

or the frame of a pair of

eyeglasses Glasses, also known as eyeglasses or spectacles, are vision eyewear, with lenses (clear or tinted) mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms (known as temples or ...

. This allows what is behind to be checked continuously without turning round. Rear-view mirrors almost never come with a new bicycle and require an additional purchase.

Aircraft

In 1956, the Civil Aeronautical Administration proposed a rear-view mirror mounted right above the pilot to keep an eye when private aircraft are landing or taxiing on the runway to prevent collisions. Fighter aircraft usually have one or more rear-view mirrors mounted on the front canopy frame to watch out for chasing aircraft.

Computer monitors

Some computer monitors are fitted with rear-view mirrors to see if anyone is positioned behind the user where they can see sensitive information, such as names and passwords, being keyed in or on the screen. These are used especially on

automated teller machine An automated teller machine (ATM) or cash machine (in British English) is an electronic telecommunications device that enables customers of financial institutions to perform financial transactions, such as cash withdrawals, deposits, fun ...

s and similar.

References

{{DEFAULTSORT:Rear View Mirror 1911 introductions Mirrors Vehicle parts