Wing mirror

A wing mirror, also known as the fender mirror, door mirror, or side view mirror, is a mirror found on the exterior of motor vehicles for the purposes of helping the driver see areas behind and to the sides of the vehicle, outside of the driver's peripheral vision (in the 'blind spot').

For mirrors on bicycles and motorcycles see "Rear-view mirror".

Although almost all modern cars mount their side mirrors on the doors, normally at the A-pillar, rather than the wings (fenders – portion of body above the wheel well), the "wing mirror" term is still frequently used.

The side mirror is equipped for manual or remote vertical and horizontal adjustment so as to provide adequate coverage to drivers of differing height and seated position. Remote adjustment may be mechanical by means of bowden cables, or may be electric by means of geared motors. The mirror glass may also be electrically heated and may include electrochromic dimming to reduce glare to the driver from the headlamps of following vehicles. Electrochromic auto-dimming technology relies on a layer of electrochromic gel placed between two pieces of side mirror's glass and light sensors that measure brightness of the following vehicle's headlights and compare it to the brightness of ambient light. These inputs are used to dim the mirror. Increasingly, the side mirror incorporates the vehicle's turn signal repeaters. There is evidence to suggest mirror-mounted repeaters may be more effective than repeaters mounted in the previously predominant fender side location.

In the 1940s many roads were unmade and had two lanes, one in each direction. Drivers had to be aware only of traffic on their side and directly behind them (rear view). Due to this, most passenger vehicles with an internal rear-view mirror until the late 1960s had the passenger-side mirror only as an optional addition, as it was considered a luxury.

In the U.S. and Canada, the U.S. National Highway Traffic Safety Administration's Federal Motor Vehicle Safety Standard 111 and the Canada Motor Vehicle Safety Standard 111 require the driver side mirror to provide "unity magnification", i.e., an undistorted 1:1 reflection achieved with a flat mirror. However, unity magnification limits the field of view that can be provided by a mirror of size compatible with the vehicle body. The ECE regulations in use throughout most of the world except North America permit the driver side mirror to have a planar, convex, or aspheric surface; an aspheric section is often combined with a larger convex section, and the two sections are separated by a visible line to alert the driver to the two sections' different perspective shifts.

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Wikipedia