"The mirrors darken automatically in proportion to how bright the glare is, then clear once the glare is no longer detected. The technology is called electrochromics, which applies electricity in order to tint glass through a low-voltage power supply. The electricity moves through an electrochromic gel placed between two pieces of glass during manufacturing, which have been treated with an electrically conductive coating." Read more: How Do Auto Dimming Mirrors Work? | eHow.com http://www.ehow.com/how-does_5003057_auto-dimming-mirrors-work.html#ixzz26Ycv4sRV
