What is the difference between automatic anti-glare and manual anti-glare?

[LeMichael]

Automatic anti-glare and manual anti-glare differ in the following aspects: Different components: The anti-glare rearview mirror consists of a special mirror, two photodiodes, and an electronic controller. The electronic controller receives signals of front and rear light from the photodiodes. It can be divided into manual anti-glare rearview mirrors and automatic anti-glare rearview mirrors. Different working principles: Working principle and characteristics of manual anti-glare rearview mirrors: They use a mirror with two reflective surfaces. During the day, the surface with higher reflectivity is used, and at night when there is strong light from behind, it needs to be manually adjusted to the surface with lower reflectivity. Although this can prevent glare, this ordinary anti-glare rearview mirror is troublesome to use as it requires manual adjustment according to the environment. Working principle and characteristics of automatic anti-glare rearview mirrors: When light shines on the interior rearview mirror, if the light from behind is stronger than that from the front, the electronic controller will output a voltage to the conductive layer. This voltage changes the color of the electrochromic layer on the mirror surface. The higher the voltage, the darker the color of the electrochromic layer. At this time, even if strong light shines on the rearview mirror, the light reflected to the driver's eyes by the anti-glare interior rearview mirror will appear dim and not dazzling, making it more intelligent.

[VanAnna]

I used to drive a car with a manual anti-glare rearview mirror, which had a small lever under the mirror. Every time I was dazzled by the high beams of a car behind me, I had to free up a hand to flip that lever. If I was slow, my eyes would be dazzled. Now I've switched to an automatic anti-glare one, completely freeing my hands. It has a hidden sensor inside, and the moment it detects strong light, the mirror instantly darkens, reacting very quickly. Once on the highway, I encountered a truck with high beams on, and the rearview mirror automatically turned green, completely eliminating the glare. However, the automatic version is indeed much more expensive; the manual one can be managed for just a few dozen bucks, but the automatic one is way more convenient.

[CharlieFitz]

Technically, there's a significant difference between the two. Manual anti-glare relies purely on physical mechanisms, reducing reflections by adjusting the mirror's angle. The automatic version uses optoelectronic technology with electrochromic materials sandwiched in the mirror. When sensors detect strong light from behind, they trigger an electrical reaction to darken the mirror. I remember driving a friend's car once - emerging from a tunnel when headlights hit directly, that auto-dimming mirror darkened faster than I could blink. However, these high-tech systems require regular sensor maintenance. My old car once suffered delayed response precisely because of dust accumulation on the sensors.

[HectorLynn]

In my opinion, the biggest issue with manual anti-glare is the safety hazard. The worst thing when driving at night is suddenly being blinded by strong light. With manual ones, you first have to identify the light source direction and then operate the lever, which takes at least two seconds of distraction. I almost rear-ended someone once because of this. Automatic systems don't have this concern - they detect strong light and handle it immediately with zero operation required. But automatic systems rely on electricity, so if the battery is low, they stop working. Plus, the cost of replacing one automatic mirror could buy seven or eight manual mirrors. If you don't drive much, there's really no need to spend the extra money.