For those of you not privileged enough to have driven a car with
a light reactive rear view mirror.
Should be forgiven for not knowing what one is.
The electro chromatic rear view mirror as BMW call it is a rear view mirror which is electrically powered to react to light. Just like a pair of reactolite sunglass's.
The mirror works as the car behind gets closer and it's headlights brighter, it adjusts by darkening and therefore making the bright light less irritating on your eyes. What a must!!!!
Given that this item is generally only fitted to high specification cars most of us will have to do without. But they are becoming more popular. soon we all may benefit from such a luxurious item.