The mirror itself darkens when a light source hits it, thanks to electrochromism (which is why auto-dimming mirrors are also called electrochromic mirrors). An electrochromic material changes colour when charged by an electrical current. Send voltage through it, and it darkens. Remove the voltage, and it lightens.
How do I know if my mirror is auto dimming?
The easiest way to see if it’s working is, when there’s a car behind you with lights on, cover the front sensor — the mirror should get brighter. Take your hand away from the sensor and it should dim again.
How far should you be able to see in your rearview mirror?
Legally, your mirror has to be located in a position that allows the driver to view the road behind them for a minimum distance of 200 feet.
What does dimming mirror mean?
An auto-dimming mirror fights glare that can cause the Troxler Effect by actually darkening the mirror—via a process called electrochromism—when an ambient light sensor detects glare from the tailing car’s headlights.
How do you use auto dimming mirrors?
In auto dimming mirror technology, a forward-looking sensor detects low ambient light from headlights behind the car and directs the rear-view sensor to look for glare. The mirrors darken automatically in proportion to how bright the glare is, then clear once the glare is no longer detected.