Headlights are used to provide illumination for night-time driving. In addition, daytime running lights improve the ability of other drivers to see your vehicle. While there have been many types of headlight bulbs throughout history, two types most popular today are halogen and high-density discharge. Halogen bulbs are standard with most vehicles and can replace non-halogen bulbs in older vehicles.
The first headlight was an acetylene lamp with a reflective mirror behind the flame. This type of headlight was used for carriages during the 1800s. The first electric light was available in 1898 for use on the first electric car. Around 1910, Corning Glass Company developed the first lens-focused headlight. High and low beam headlights were introduced in 1915 by the Guide Lamp Company. The terms, "high" and "low" beam quite literally meant that the headlights were directed high or pointed low. Initially, the headlight position was manually changed. Osram developed dual-filament high and low beam bulbs in 1924. Sealed beam headlights, in use between 1940 and 1983, were a single unit that contained the bulb and lens. When the lamp burned out, the entire unit was replaced. Beginning in 1983, composite headlights were available in which only the bulb required replacing when it burned out.
Halogen headlight bulbs are the most commonly used bulbs in vehicles. These headlight bulbs use a filament similar to a regular light bulb's. The bulb is filled with halogen gas that provides consistent light throughout the life of the bulb. Halogen bulbs last about 300 hours before burning out. Older vehicles had standard gas headlight bulbs that are no longer available. These bulbs can be replaced with comparable halogen bulbs.
HID headlight bulbs create almost twice the light, have less light fading at the edges of the bulb and last longer than halogen bulbs. They are also available in a variety of tones, such as bluish-white, violet-white and greenish-white. HID bulbs do not require a filament. The bulb is filled with xenon gas, which creates light with an arc of electricity. Many vehicles require alterations to the headlight wiring to be able to use HID bulbs.
When considering the purchase of headlight bulbs online, keep in mind there are Department of Transportation restrictions on some types of headlight bulbs. Check with your local auto care store to be sure the bulbs you choose are within the guidelines set by your state Department of Transportation.
When replacing headlight bulbs, do not touch the glass part of the bulb. This can cause the bulb to burst when heated during use or shorten the life of the bulb. Headlight bulbs should always be replaced on both sides when one burns out. Purchase replacement bulbs designed for the make and model of your vehicle. Consult the owner's manual for the headlight specifications for your vehicle.
