Share Blog:
Copy Link

Electronic rearview mirror review: Advantages and Disadvantages

電子倒後鏡的優點和缺點
Author
Kwiksure Team
Created On
2020-01-14
Edited On
2026-05-18
Text Size

Most of us have driven at night only to be blinded by the glare of headlights shining from behind, making it impossible to see what else is at the back and impairing our vision as well. While you can manually adjust the mirror by flicking a switch, changing the mirror to the nighttime driving mode dims almost everything else and makes it difficult to see out of the mirror. That’s where electronic rearview mirrors come in. 

In this Kwiksure article, we’ll go over electronic rearview mirrors, including the advantages and disadvantages of using them. 

Table of contents
  • What is an electrochromic rearview mirror?
  • How does the rearview mirror dimming work?
  • Advantages of electronic rearview mirrors
  • Disadvantages of electronic rearview mirrors
  • Choosing an electronic rearview mirror
  • How to install a rearview mirror

What is an electrochromic rearview mirror?

Electrochromism is a term used to describe when the color in a substance changes due to the application of an electric current. The change can be reversed as well. Upon sensing light from behind, an electrochromic rearview mirror, which is also known as an electronic or electric rearview mirror, dims automatically. This helps reduce glare that would otherwise be problematic for driving. 

經快而保買獨立交強險/商業險,出單快捷方便,符合內地需求!

How does the rearview mirror dimming work?

Electronic rearview mirrors sense light and dim accordingly. Here’s how.

Sensing light

The electronically-operated mirror uses a combination of light sensors and an electrochromic gel that changes color when it either gains or loses electrons due to an electric current. The gel sits between two pieces of glass, which has a clear coating that conducts electricity. Additionally, one piece of glass has a reflector. 

The mirror system features a sensor that faces the front of the vehicle. Sensitive to low levels of light, the sensor signals the mirror to identify signs of glare. Similarly, the second sensor faces towards the rear of the vehicle and recognizes glare from cars coming from behind. 

Dimming 

Upon detecting glare from behind, the second sensor sends current to the gel in the mirror. This creates a voltage that corresponds to the amount of glare detected, causing the mirror to quickly dim on its own. The mirror returns to its normal state when glare is no longer detected by the sensor. The electrochromic mirror system is capable of dimming both external and internal mirrors. 

Eliminating glare 

Electronic rearview mirrors improve driving safety by getting rid of glare that can affect vision. Glare from the headlights of trailing vehicles makes it harder to see what’s in front, making it especially dangerous when driving on dark roads with cross-traffic and areas where animals may cross the road. 

比較全港逾60間保險公司報價,快而保汽車保險中介為你挑選最符合你要求的車保,立即報價!

Advantages of electronic rearview mirrors

As we previously mentioned, the mirrors dim automatically, reducing glare and discomfort. What’s more, they dim proportionately to the amount of light that reaches them, allowing the mirror to dim more when headlights are brighter or closer to your vehicle. The advantages of these mirrors include: 

  • Auto-dimming technology guarantees the right amount of dimming at any given time
  • Eliminates the need to manually adjust the mirror when driving at night
  • More transparent view than conventional rearview mirror technology
比較全港逾60間保險公司報價,快而保汽車保險中介為你挑選最符合你要求的車保,立即報價!

Disadvantages of electronic rearview mirrors

Any electronic object can malfunction, which may occur at inopportune moments, if at all. In addition, auto-dimming rearview mirrors are more difficult to repair than conventional rearview mirrors. Electronic rearview mirrors also take time to get used to, since you will probably attempt to manually adjust them at first out of habit. 

經快而保買獨立交強險/商業險,出單快捷方便,符合內地需求!

Choosing an electronic rearview mirror

When it comes to selecting an electronic rearview mirror, you’ll notice that there are different styles and brands available. Many electronic rearview mirrors also come with thermometers, compasses, and garage door openers. It’s best to choose a mirror from a trustworthy brand, such as Gentex or CIPA. As for the style, go for one that provides the view and added features that you’re after.

For example, the Gentex mirror comes in multiple styles to match your exact needs. You can choose one with a camera or one with a compass. Likewise, there are no blind spots and panoramic styles available as well.

經快而保買獨立交強險/商業險,出單快捷方便,符合內地需求!

How to install a rearview mirror

Some electronic rearview mirror models are easily installed by simply clipping them over your existing rearview mirror. Other models are slightly trickier to install on your own, though every car mechanic can easily do it for you. Installing a rearview mirror on your own only takes a few simple steps. 

  1. Remove the existing mounting button from the rearview mirror. 
  2. Make the windshield warm, such as by using a hairdryer. 
  3. Remove old adhesive and clean the windshield. 
  4. Mark exactly where you want to install the bracket. 
  5. Apply an activator on both surfaces. 
  6. Place glue on the mounting button and bracket instead of the windshield. 
  7. Attach the rearview mirror to the bracket. 

It’s easy to see why an electronic rearview mirror would be a good addition to your car. After all, your safety, as well as your passengers’ safety, comes first and making your car safer is worth the investment. 

If you’re looking for motor insurance in Hong Kong, our experts at Kwiksure are happy to help you at any time. As Hong Kong’s leading car insurance broker, Kwiksure can help you find the best third party insurance and comprehensive insuranceContact us or visit our website for a free, no-obligation quote today. 

經快而保買獨立交強險/商業險,出單快捷方便,符合內地需求!

Contact Kwiksure to get motor insurance quotes

Kwiksure has over 20 years of experience in the car insurance industry, comparing quotes from over 60 insurers in Hong Kong. Use our online quotation tool now to get a free car insurance quote!

The above information is for reference only. Kwiksure takes no responsibility for the accuracy and timeliness of the information. For the coverage, mode of compensation, benefit limit and premium levels of any specific insurance plan, please refer to the relevant policy terms.

kwiksure_team
Author
Kwiksure Team

Kwiksure is a licensed motor insurance brokerage company with over 20 years of experience in insurance. The company strives to simplify insurance and select the best insurance plans for customers that fit their budget and coverage needs.

Kwiksure provides a range of insurance products, including car insurance, motorcycle insurance, cross-border insurance between Hong Kong and Mainland China, home insurance, travel insurance, domestic helper insurance, and voluntary medical insurance. The team has been named "Best Car Insurance Broker" and "Outstanding Leadership Award" by various media outlets over the years.

【行車證到期】2025全新行車證特點|各類車輛牌費價錢|續牌文件及三大方法(連電動車牌費計數機)
Car
2025-06-28

[Vehicle License Renewal] Features of New Vehicle Licenses 2025| License Fees for Different Types of Vehicles | Renewal Documents and Three Main Methods (Including EV License Fee Calculator)

The Hong Kong government requires all vehicles to hold a valid vehicle license (commonly known as a 'driving permit') to operate on public roads. How much does it cost to renew the licenses for private cars, vans, and motorcycles? Are there differences in calculating the license fees for electric vehicles? What are the procedures and required documents for renewing the licenses of new and used vehicles? How long is a vehicle license valid for? What should you do if it expires? Kwiksure is here to answer all these questions.
【超速扣分】扣幾多分停牌?5大司機常犯扣分事項!附全港九新界30個影快相熱點
Car
2025-12-22

Hong Kong Traffic Offence Points: License Suspension & 30 Speed Camera Hotspots

The Driving Offence Points System has been implemented in Hong Kong for over 40 years. Simply put, certain traffic offenses incur penalty points. When a driver commits a traffic offense and is convicted by a court, or is required to pay a fixed penalty, they will receive deduction points. But how many points lead to a license suspension, what are the common deduction offenses, and what happens if a P-plate driver gets points? This time, Kwiksure will provide a detailed explanation of the driving offense points system, along with popular speed camera spots across Hong Kong, helping everyone become a safer driver. Kwiksure has over 25 years of experience specializing in motor insurance , comparing over 60 insurance companies to offer extremely low premiums for both Comprehensive and Third-Party insurance.
【車CAM】10款行車記錄儀推介+消委會評測準則(連價錢及安裝方法)
Car
2024-11-11

10 Dash Cam Recommendations for 2024 plus Installation Tips

For drivers, besides car insurance, a device commonly called a dash cam is essential to ensure the safety of themselves and passengers. For starters, in a traffic accident, the video footage can provide evidence of who caused the accident. Secondly, if there are unruly passengers, the dash cam footage can serve as evidence to protect drivers from false accusations. However, with so many dash cams on the market, how should one choose a suitable dash cam? This Kwiksure article summarizes the Consumer Council's testing criteria and recommends 10 dash cams, clarifying the characteristics of different types.
2024持續進修基金學車好唔好?5間駕駛課程費用比較及評價|李健、駕院、貨櫃業職工總會
Car
2024-03-19

Learning to Drive with Continuing Education Fund (CEF) 2025

The government's Continuing Education Fund (CEF) has recently increased its subsidy to HK$25,000, and covers driving courses from the Hong Kong School of Motoring, Lee Kin Driving School, and the Container Transportation Employee General Union. After deducting the subsidy amount, learners only need to pay around HK$5,000 to HK$6,000. In this article, Kwiksure compares the course content, number of lessons, graduation requirements, and fees of these three schools. We’ll also explain the application process for the Continuing Education Fund and provide a brief introduction to the driving courses of two non-CEF schools, A1 Driving School and Hung Chun Driving School, for your reference.
【撞車/交通意外處理懶人包】幾時報保險?連和解書範本 | 流程與賠償時間詳解
Car
2025-12-11

The Ultimate Guide to Handing Car Crashes in Hong Kong 2025 (With Settlement Agreement Template)

With so many easily agitated drivers and narrow lanes, it’s little wonder road accidents happen quite often in Hong Kong. Every driver, experienced or not, should learn how to handle an accident as part of their training. If you don’t want to be hastily looking up information right when you need it, you should learn how to respond to a road accident now. Otherwise, if you take the wrong steps, not only can your motor insurer reject your claim application, you could even end up in legal hot water! There are a myriad of different opinions on what are the proper steps for handling a road accident. Different drivers will give different answers to questions such as "Can the parties simply settle the matter themselves?", "Do I have to notify my insurer within 24 hours?", or "Will I be denied compensation if I said sorry?". Today, the experts at Kwiksure will explain the right steps to take after a road accident, and point out some of the most common fallacies.
混能車推介2025 l 比較17款香港混能車|型號、售價、賣點|優缺點分析
Car
2023-11-27

[Hybrid Car Recommendation 2025] Comparison of 17 Hong Kong Hybrid Cars | Models, Prices, Selling Points | Pros/Cons Analysis

With the innovation of automobile technology, in addition to the popular Electric Vehicles . In addition, it combines the power of the engine and the electric motor, and is sold as fuel-saving. Hybrid vehicles have also attracted much attention in Hong Kong. In this article, Kwiksure will explain the different types of hybrid vehicles and analyze their advantages and disadvantages, and recommend 17 hybrid vehicles for your reference. Kwiksure has over 25 years of experience in car insurance , comparing over 60 insurance companies and offering ultra-low full coverage and triple coverage premiums.