April 01, 2022 5 min read
Considering how small headlamps are nowadays, they are packed with handy and potentially life-saving features.
With all these features, it can become hard to know what they do, and even if you really need all of them. All of these features, from different colored bulbs, brightness settings, and strobe effects, each have a purpose which might not be obvious.
One feature, in particular, is that nearly all headlamps come with the ability to shine red light as well as white.
In this article, we'll be looking at the practical reasons why headlamps have a red light feature, and what the purpose of this is. So if you're looking for a new headlamp, or are simply curious about the purpose of a red light on a headlamp, read on!
The short and sweet answer to this question is simple: red light is less impairing than traditional white light and as such, improves your vision at night. Red light is less harsh, so it makes it easier for a cyclist’s eyes to adjust to this color light in the nighttime.
Headlamps have a red light to aid cyclists who are riding at night. As red light improves your night vision, it allows your eyes to maintain their focus whilst providing enough light to see. In short, the purpose of the red light is to provide light to a cyclist that will not strain their eyes.
Whilst the red light on a headlamp's main aim is to aid cyclists riding at night, this feature can be used by anyone. So, there are lots of situations where it could come in handy. From night hikes to stargazing, a red light on a headlamp is extremely useful.
It would seem like every single headlamp manufacturer out there has included a red light feature on their product. This isn't just because they think it's cool, but also because it's useful in some situations.
As we've discussed, when cycling at night, a cyclist will often use a headlight to illuminate their surroundings so that they don't run into any obstacles. However, since the human eye is more sensitive to blue light than other colors, using a white light could cause issues for the user.
A red light, however, is much less likely to cause problems for the user, as it only affects the color spectrum of the light source, rather than the entire range of visible wavelengths.
This means that a red light doesn't impact the way your brain processes information, meaning that you won't experience any visual impairment.
This makes a red light ideal for nighttime cycling, as it provides an improved visibility without causing any damage to your eyes.
Our pupils dilate when they react to different light intensities. This is a normal function of healthy eye activity and doesn't explain the cause of nighttime blindness.
When we expose our eyes to light, especially in dark environments, a chemical in our eyes known as Rhodopsin becomes bleached, and loses its effectiveness.
This chemical is extremely light-sensitive that sits in the rods of the retina. It can take up to 30 minutes for rhodopsin to regenerate after it has been bleached.
It is less sensitive to red light, which explains why our light perception isn't affected when using a red light to see.
However, when you're exposed to bright lights, especially those containing blue light, your rod cells start to regenerate faster. When this happens, your pupils constrict, resulting in reduced visibility.
If you were to cycle at night, and use a white light, your rod cells would quickly become exhausted and unable to regenerate, resulting in a loss of night vision.
This is why many people find themselves struggling to see objects while cycling at night. Using a red light, however, ensures that your rod cells remain active, allowing you to continue seeing clearly.
In addition, studies show that when you're exposed to a high level of light, your rod cells begin to produce melatonin, a hormone that helps regulate sleep patterns.
Aside from the obvious benefits, like impairing your vision a great deal less at night, here are some other benefits to red lights on a headlamp:
There are two main types of red lights available:
LEDs also come in a variety of colors, including yellow, orange, green, and blue. You should choose one that best suits your needs. For example, if you want to be able to see more clearly, go for an amber or yellow LED. If you want to prevent your eyes from getting tired, go for a cool-colored LED.
Incandescent bulbs tend to be cheaper than LEDs, but they lack versatility. They only emit light in one color, so you'll need to buy multiple bulbs to get all the colors you require.
As with most things, there are downsides to using a red light on a headlamp. It goes without saying that if it were so beneficial, every street lamp or headlight on a car would emit red light.
Most headlamps, especially the higher end ones, have at least a dozen white LEDs and at most two red LEDs. Whilst red light is kinder to the eyes, it is less effective at illuminating areas than white light.
Whilst all of the above stands true, all light at night affects your vision. That being said, on cheaper headlamps, manufacturers tend to use one bright red LED, which will still impact night vision.
This question ultimately comes down to personal preference. Some cheaper headlamps don't come with a red LED, so your budget also plays a part.
There's no specific law surrounding which type of light to use at night.
If you're looking to improve your night vision, then a red light on a head lamp is definitely worth considering. However, make sure you know what type of light you're buying first!