Most of us have driven at night only to be blinded by the glare of headlights shining from behind, making it impossible to see what else is at the back and impairing our vision as well. While you can manually adjust the mirror by flicking a switch, changing the mirror to the nighttime driving mode dims almost everything else and makes it difficult to see out of the mirror. That’s where electronic rearview mirrors come in.
In this Kwiksure article, we’ll go over electronic rearview mirrors, including the advantages and disadvantages of using them.
How does the rearview mirror dimming work?
Electronic rearview mirrors sense light and dim accordingly. Here’s how.
Sensing light
The electronically-operated mirror uses a combination of light sensors and an electrochromic gel that changes color when it either gains or loses electrons due to an electric current. The gel sits between two pieces of glass, which has a clear coating that conducts electricity. Additionally, one piece of glass has a reflector.
The mirror system features a sensor that faces the front of the vehicle. Sensitive to low levels of light, the sensor signals the mirror to identify signs of glare. Similarly, the second sensor faces towards the rear of the vehicle and recognizes glare from cars coming from behind.
Dimming
Upon detecting glare from behind, the second sensor sends current to the gel in the mirror. This creates a voltage that corresponds to the amount of glare detected, causing the mirror to quickly dim on its own. The mirror returns to its normal state when glare is no longer detected by the sensor. The electrochromic mirror system is capable of dimming both external and internal mirrors.
Eliminating glare
Electronic rearview mirrors improve driving safety by getting rid of glare that can affect vision. Glare from the headlights of trailing vehicles makes it harder to see what’s in front, making it especially dangerous when driving on dark roads with cross-traffic and areas where animals may cross the road.
