See How Projector Headlights Work! The very first electric headlights of vehicles used were reflective. This consists of a bulb in a steel bowl with tiny mirrors that act as reflectors and throw light. Reflector headlights are still in use as they take lesser space in the vehicle’s build and are cheaper. But as with anything, technological advancements keep pushing innovations and introducing products that improve functionality. Introducing the Projector headlights! How Projector Headlights works are fascinating! Projector headlights were first introduced to luxury cars in the 1980s but now are found commonly in most cars. 


What is a projector headlight? How Projector Headlights Work?

how projector headlights work

Similar to a reflective headlight, the projector headlight also houses a bulb in a steel bowl. The steel bowl has a more elliptical shape and has tiny mirrors that act as reflectors. That is something it has in common with reflective headlights. But the main difference is that a lens is used to ‘project’ the light reflected from the mirrors. 

How projector headlights work?

How a projector headlight works is down to simple physics. The elliptical shape of the steel bowl that houses the bulb helps to narrow the focus of the light reflected from the steel bowl. This focal point meets the ‘shutter’. The shutter cuts off an angle of the light emitted to prevent the spread of the light to the point above the road.

The shutter is an important element of the projector headlight that enables brighter light without blinding oncoming traffic. It acts as a barrier from below to prevent the unnecessary angle of the light emitted from even meeting the lens. So while the lens can magnify and brighten the light emitted, the shutter cancels off light that goes above the reach of the road and could cause blinding the driver of an oncoming vehicle. The lens also plays a crucial role in evenly distributing the light as well. A reflector headlight tends to have dark spots in its lighting.

This innovation allows projector headlights to be fitted with a variety of bulbs. The halogen bulbs are the regular bulbs used even in reflector headlights. However, in a projector headlight, the halogen bulbs emit a more even light. HID lights can be used which are brighter and last longer but need to be fitted on projector headlights meant for HID lights and not Halogen lights. LED bulbs are more energy-efficient and last very long if there is no damage to them. It can even outlast your car!

Advantages of using Projector Headlights

how projector headlights work
  • Brighter, Even Light: Projector headlights emit brighter and more even light, void of dark spots as seen in reflector headlights.
  • Focussed Light: A Projector headlight does not blind oncoming traffic as it uses a shutter.
  • Better Bulbs: Projector headlights can use HID or LED bulbs that are brighter and last longer. These cannot be fitted into a reflector headlight. Doing so would blind oncoming traffic.


1. How do halo projector headlights work?

Halo headlights are referred to as Angel Eyes due to their appearance as a circular rim around the actual headlights. This was first seen in 2001 in BMW’s 5 Series. These serve as daytime running lights. Halo lights consist of incandescent bulbs. CCFL halo bulbs use cold cathode fluorescent lighting tubes that burn brighter than incandescent bulbs and have no dark spots. LED halo rings are also available and can be bought in different colors.

2. Can I replace my vehicle’s reflector headlights with projector lights?

This is possible. First, you need to check if your vehicle has a projector headlight kit available that can easily be fitted in. Or you will need to check if the universal projector headlights kit can be fitted. This needs to be done carefully and preferably by a professional.

3. Can I fit an HID bulb in a reflective headlight to make it brighter?

No. This is not advisable at all. HID bulbs in a reflective headlight will blind oncoming traffic as it does not have a shutter element to them. This can prove to be very dangerous.