A sun visor is a component of an automobile

Automobile

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

 located on the interior just above the windshield

Windshield

The windshield or windscreen of an aircraft, car, bus, motorbike or tram is the front window. Modern windshields are generally made of laminated safety glass, a type of treated glass, which consists of two curved sheets of glass with a plastic layer laminated between them for safety, and are glued...

 (also known as the windscreen).

Most cars have two sun visors, one for the driver's side and a second for the passenger's side, with the rear-view mirror

Rear-view mirror

A rear-view mirror is a mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's backlight ....

 often mounted in between the two sun visors. Each visor can be lowered to help block light from the sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

 entering through the windshield. They can also be turned to the front side window to reduce lateral sun exposure.

Many sun visors also incorporate a vanity mirror

Mirror

A mirror is an object that reflects light or sound in a way that preserves much of its original quality prior to its contact with the mirror. Some mirrors also filter out some wavelengths, while preserving other wavelengths in the reflection...

 for the passenger's convenience. In some cases, a flip up cover over the mirror automatically turns on the vanity lights, which can be adjusted with a sliding dimmer

Dimmer

Dimmers are devices used to vary the brightness of a light. By decreasing or increasing the RMS voltage and, hence, the mean power to the lamp, it is possible to vary the intensity of the light output...

 control (see image).

Recently, sun visors incorporating LCD screens, DVD players and other devices have become available as an aftermarket modification. They are also available as an option or standard item from manufacturers with garage door opener systems such as HomeLink

Homelink

Homelink was the UK's first online banking system. It was set up by the Nottingham Building Society in 1983 in association with the Bank of Scotland, using the UK Post Office's Prestel Viewdata system....

built into the visors.

Exterior sun visors are available for trucks as cab visors.