Auto-dimming interior rearview mirror
ConfortAverage price
150€ - 500€
The auto-dimming interior rearview mirror, also known as an automatic day/night mirror, is a comfort and safety feature that automatically darkens to reduce glare caused by the headlights of trailing vehicles. Unlike traditional manual mirrors that require physical adjustment to switch between day and night modes, the electrochromic model adjusts its tint level progressively and autonomously. It consists of special glass incorporating an electrochemical gel or liquid between two layers. Two light sensors, one facing forward (measuring ambient light) and the other facing backward (detecting headlight intensity), work in tandem. When the rear sensor detects bright light while the front sensor perceives darkness, a microprocessor sends a low electrical current to the gel, which darkens. This chemical reaction absorbs light and decreases the intensity of the reflection, thereby protecting the driver's eyes. As soon as the intense light source disappears, the current is cut, and the mirror returns to its maximum clarity. This sophisticated technology significantly improves visual comfort and safety during nighttime driving.
Benefits
- ✓Automatic reduction of headlight glare
- ✓Significant improvement in nighttime driving safety
- ✓Increased driving comfort by eliminating manual adjustments
- ✓Preservation of the driver's nocturnal visual acuity
Learn more
What is an auto-dimming interior rearview mirror?
The auto-dimming interior rearview mirror is a major technological innovation for automotive comfort and safety. Often referred to as an 'automatic day/night mirror', its primary function is to protect the driver from the potentially dangerous glare caused by the headlights of trailing vehicles at night. Rather than having to manually flip a lever, this system automatically and progressively adjusts the mirror's tint to provide optimal visibility in all nighttime conditions. It represents a significant evolution over manual systems, providing an 'smart' solution to a common problem.
How does this anti-glare technology work?
The operation of the electrochromic rearview mirror relies on a sophisticated electrochemical principle. The mirror is not a simple reflective surface; it is a complex assembly containing an electrochemical gel or liquid sandwiched between two glass plates.
The system is controlled by two light sensors:
- An ambient light sensor: Generally located on the front of the mirror (windshield side), it detects the general brightness level. It allows the system to know whether it is day or night.
- A glare sensor: Positioned on the mirror itself, it faces the rear of the vehicle and measures the light intensity of the following cars' headlights.
When the vehicle is driving at night (the ambient sensor detects darkness) and a trailing vehicle with bright headlights approaches (the rear sensor detects high luminosity), a microprocessor applies a low electrical voltage to the electrochemical gel. This voltage triggers a redox reaction that darkens the gel. The more intense the detected light, the darker the gel becomes, thereby absorbing excess light and reflecting only a dimmed, glare-free image to the driver. The process is fully progressive and reversible: as soon as the light source diminishes, the voltage is cut and the rearview mirror returns to a perfectly clear state.
What are the main advantages of the auto-dimming rearview mirror?
Adopting this technology offers multiple benefits that enhance the driving experience.
- Increased safety: By eliminating glare, the auto-dimming rearview mirror prevents temporary blindness and eye fatigue. The driver can remain focused on the road ahead without being distracted or bothered by what is happening behind.
- Optimal driving comfort: Complete automation of the system means the driver no longer has to worry about adjusting their mirror. Gone is the motion of flipping the tab, which is often awkward while driving. Visual comfort remains constant.
- Better preservation of night vision: The human eye takes time to adapt to the dark. Being exposed to flashes of bright light can ruin this adaptation. The electrochromic mirror maintains a stable brightness level, helping the driver's eyes stay acclimated to low-light conditions.
- Technological integration: On many modern vehicles, the driver's side exterior mirrors are also electrochromic and synchronized with the interior rearview mirror, offering comprehensive anti-glare protection.
Availability and option cost
Once reserved for high-end vehicles, the auto-dimming interior rearview mirror has become widely democratized. Today, it is offered as standard on most upper trim levels of mainstream manufacturers such as Peugeot, Renault, or Volkswagen, and remains a standard among premium brands like BMW, Audi, and Mercedes-Benz. On intermediate trim levels, it is often included in 'Comfort Packs' or 'Visibility Packs' for a modest additional cost, generally between €150 and €500 depending on the pack and the manufacturer. Given the significant gain in comfort and safety, it is a highly recommended investment for drivers who regularly travel at night.
Finitions équipées
72 finition(s) proposent cet équipement
Toyota Toyota Verso-S
Executive (1st generation) (2012-2015)
Toyota Toyota Yaris
Collection (3rd generation XP130) (2011-2020)
Toyota Toyota Yaris Cross
Dynamic (2024 facelift - 1st generation) (2024-2026)
Volkswagen Volkswagen CC
Carat (1st generation - Passat CC) (2010-2012)
Volkswagen Volkswagen Jetta
Carat (6th generation A6) (2011-2016)
Volkswagen Volkswagen Passat
Carat Edition (B7) (2012-2014)
Volvo Volvo S40
Summum (2nd generation) (2010-2012)
Volvo Volvo V40
Summum (Phase 1) (2012-2016)
Volvo Volvo V50
Summum (1st generation) (2010-2012)
Volvo Volvo V70
Momentum Business Elegance (3rd generation) (2013-2015)
Škoda Škoda Octavia
Elegance (Octavia III) (2013-2017)
Škoda Škoda Yeti
Elegance (1st generation - phase 1) (2010-2013)
Associated equipment
Automatic headlight activation
Automatic headlight activation is a driver assistance system designed to improve safety and driver comfort. Using a light sensor, usually located on the upper part of the windshield near the rearview mirror, the vehicle detects variations in ambient light. When the light level drops below a predefined threshold, such as at dusk, when entering a tunnel, in an underground parking lot, or during heavy weather, the system automatically commands the activation of the low beam headlights and tail lights. Conversely, when the light level becomes sufficient again, the lights turn off by themselves. This automation frees the driver from any manual intervention, allowing them to focus fully on the road. In addition to ensuring optimal visibility under all circumstances, this device prevents potentially dangerous oversights and avoids fines related to a lack of regulatory lighting. Often coupled with automatic windshield wipers, it is now standard equipment on the majority of new vehicles, actively contributing to active and passive safety.
Light sensors
The light sensor is a fundamental electronic component in Advanced Driver Assistance Systems (ADAS), playing a crucial role in active safety and comfort. Typically housed in a compact unit at the base of the windshield, behind the rearview mirror, it is very often combined with the rain sensor. Its primary function is to continuously measure ambient light intensity using one or more photodiodes. When this light intensity falls below a predefined threshold (dusk, entering a tunnel, underground parking, heavy rain), the sensor sends a signal to the Body Control Module (BCM). The BCM then instantly activates the automatic low-beam headlights and tail lights, ensuring the vehicle remains visible and the driver benefits from optimal visibility without any manual intervention. Beyond this main function, the light sensor actively contributes to cabin visual comfort. It controls the adjustment of the instrument cluster lighting intensity, the infotainment screen, and the head-up display, dimming them at night to prevent glare and eye strain. Today, this intelligent automation is standard on the majority of new vehicles.
Auto-dimming rearview mirror
The auto-dimming rearview mirror, also known as an electrochromic mirror, is a comfort and safety feature that automatically adjusts its tint to reduce glare caused by the headlights of trailing vehicles. Unlike the manual version which requires flipping a tab, this system operates completely autonomously. It consists of two light sensors: one facing the front of the vehicle to measure ambient light, and another facing the rear to detect the light intensity of headlights. An electrochemical gel is sandwiched between the two layers of glass in the mirror. When the rear sensor detects bright light (glare) while the front sensor perceives darkness, a low-voltage electric current is sent through the gel. This chemical reaction darkens the mirror progressively and proportionally to the intensity of the glare, absorbing the light and reflecting only a dimmed image to the driver. As soon as the light source disappears, the mirror instantly returns to its clear state. This technology significantly improves nighttime driving comfort and safety by preventing eye fatigue and the distractions associated with manual adjustment.
Blind Spot Monitor
The blind spot monitor, often referred to by the acronym BSM (Blind Spot Monitoring), is an Advanced Driver Assistance System (ADAS) fundamental to modern automotive safety. Its role is to monitor the lateral and rear areas of the vehicle that are invisible to the driver via the rearview mirrors or direct vision. To do this, it relies on a network of sensors, typically short-range radars hidden in the corners of the rear bumper or under the outer mirror housings. As soon as a vehicle (car, motorcycle, truck) enters this blind spot, the system alerts the driver. The warning most often takes the form of a light, usually an orange or red icon that illuminates in the outside mirror on the affected side. If the driver engages their turn signal to change lanes while a hazard is present, the alert is intensified by a rapid flashing of the indicator, often coupled with an audible signal or a steering wheel vibration. The most advanced systems, classified as active, can go so far as to apply a slight counter-steering force to discourage the maneuver and prevent a collision. Particularly effective on high-speed roads and in dense traffic, this technology has become an essential safety standard, significantly reducing the risk of lane-change accidents.