The automatic anti glare function is no longer a cutting-edge technology. Some models were adopted as early as the beginning of the century. However, in the early stages, due to its high cost, this feature was often applied to luxury cars worth millions of yuan, such as the Lexus LX. However, with the development of technology and cost reduction, the cost of automatic anti glare rearview mirrors has been controlled at around a thousand yuan. Therefore, more and more mid to low price models are also equipped with this function as standard, such as the Volvo S60/S90/XC60, as well as many models such as Mercedes Benz, BMW, Audi, etc.

So, how is the automatic anti glare function implemented? The principle mainly relies on an automatic anti glare function controller, which has two built-in photosensitive sensors. One of the sensors is used to detect surrounding light. When the surrounding light is strong, the system defaults to daytime mode and is in standby mode.

When the ambient light becomes dim, such as entering a tunnel or driving at night, the controller will combine another sensor to determine whether to activate the anti glare mode. If the rear light is weak, the system will continue to standby; If the light behind is strong, the controller will quickly respond and send a voltage signal to the electrochromic lens, causing the color of the lens to darken in a short period of time, thereby reducing the intensity of reflected light.

Experimental data shows that when the rearview mirror is in an anti glare state, its reflectivity is only about 7%. The controller is usually built into the interior rearview mirror, while the left and right rearview mirrors achieve anti glare function by receiving voltage signals sent by the interior rearview mirror.

From the demonstration video, it can be seen that after receiving the voltage signal from the controller, the color of electrochromic glass will gradually darken. As the color deepens, the intensity of the reflected light will also gradually weaken.

After understanding the principle of automatic anti glare lenses, some people may wonder if it is possible to achieve the anti glare effect by applying a dark film on the glass? The answer is yes, there are already such products on the market, such as blue or gold mirrors. However, this film application method will keep the mirror surface in a dark state for a long time, which is not conducive to observing the road conditions behind.

In contrast, automatic anti glare rearview mirrors are more intelligent. When there is strong light in the rear, the lenses will automatically darken to reduce glare; When there is no strong light behind, the lens returns to a regular white mirror, which can prevent glare under high beams and maintain a clear view during normal driving.

For models that were not equipped with this feature in their original vehicles, owners can upgrade them by adding it later.