What are the benefits of the Fenix Vitae headlamp?

 1.12.2024

The development of lighting technology over the last 100 years has brought us considerable convenience and prosperity – lighting is now very cheap and displays allow for lightning fast information transfer. At the same time, however, there is also talk of possible negative impacts that have only in recent years entered the public consciousness. So most of us have probably heard something about the potential harm of „blue light“, which is coming at us not only from screens of all kinds, but also from ordinary white LED lights at home, at work and in public spaces. So, in this post, we'll look at what effects lighting with a high blue component has and what possible solutions there are in the home and outdoors using a Fenix Vitae headlamp.

A biological clock that cannot be ignored

The harmfulness of blue light is talked about in multiple contexts. In particular, the disruption of healthy sleep within the so-called circadian rhythm, where there is already a broad scientific consensus. And it is this issue that we will now look at more closely.

Picture by Ian B Hickie et al. CC-BY-3.0

Circadian rhythms – sometimes also circadian clocks or biological clocks – are, in most organisms, natural cycles that control many biological processes throughout the day. Specifically, in humans, these include body temperature, blood pressure, production of various hormones, attention, sleep, digestion, and other bodily processes.

In most vertebrates we find this internal clock in a region of the hypothalamus called the SCN. They are constantly „adjusted“ based on various factors, but probably the greatest influence is the alternation of light and dark. Other organs and their activities are also adjusted according to this master clock in the brain. In the absence of light, the hypothalamus also produces the so-called darkness hormone melatonin, which in diurnal animals acts as a sleep hormone that prepares us for rest and regeneration. And just for the record: in nocturnal animals, melatonin leads to activity.

Circadian rhythm and blue light

And this is where artificial lighting comes into play. For millions of years, we and our evolutionary ancestors have lived exclusively according to the natural alternation of day and night. Even the taming of fire had no significant effect on circadian rhythms. Why? The retina of the eye contains different types of photosensitive cells that are tuned to different wavelengths of visible light. Specifically, the ipRGC cells are responsible for adjusting our biological clock, and they respond only to the shorter wavelengths of the light spectrum (blue, cyan, green), which are virtually absent in fire. They are not even very present in the light of classical tungsten bulbs, which by the way work on the principle of „glow“ from hot filament.

From left: Sunlight, basic LED, fluorescent bulbs,Tungsten bulbs

In contrast to incandescent lamps, however, the light spectrum of most fluorescent lamps and conventional LED sources contains a high proportion of blue components. This is why some people today live for a long time with a disrupted circadian rhythm, daytime fatigue and various sleep problems. In addition, in the last decade, new scientific studies have been published investigating the possible impact of long-lasting disrupted biological clocks on cardiovascular diseases, obesity, neurodegenerative diseases or cancer, especially in night shift workers.

First step – limiting displays

In the Czech Republic, this topic is most visibly addressed by the media-famous „luminary“ Hynek Medřický, creator of the biodynamic Vitae bulbs. In addition to these special LED sources with friendly light spectrum, Medřický offers a number of tips on how to eliminate sources of blue light in the evening and thus get a good night's sleep.

The absolute basics are to not use any lighted displays for at least 1.5 hours before you plan to sleep. And this should absolutely apply, because even a second of blue light exposure, according to Medřický, means confusion of the organism and resynchronization of the circadian rhythm.

Brightly glowing blue or green lights and small displays on various devices are also a widespread nuisance. It is advisable to tape them completely with black tape. If we do need to see them, then we can at least tape them with orange foil to filter out the distracting blue component.

Preparing for rest and activity

Some precautions beyond those mentioned should occur as early as 90 minutes before going to sleep – roughly from dinner around 6pm, depending on when one goes to bed. It is not strictly necessary to spend evenings by candlelight, but we should already be using only warm white lights. These should ideally be placed somewhere below eye level, not directly overhead like the sun at the zenith. We can also dim the blue component of all screens, usually in the normal settings under names such as „night lighting“ or „blue filter“, or you can download an app to do this.

But taking care of circadian rhythm is not just about limiting light at night. Just as important is having enough good quality light during the day to give our bodies a clear signal to be active. The ideal is, of course, sunlight as much as possible. If we do not have the opportunity to work directly outside or have a desk located by a large window, then it is advisable to invest at least in good quality lighting that is as close to sunlight as possible, i.e. with a colour temperature of „daylight white“ and positioned above us.

In addition, some full-spectrum LED sources are now produced with a balanced light spectrum without the typical peaks in the blue region and dips in the cyan region. They can be encountered under different labels such as „biodynamic lighting“, „full spectrum light“ or „circadian bulb“. At the moment, however, these are practically non-binding trade names, so it is advisable to look for expert reviews when choosing them.

Flashlights and headlamps for maintaining circadian rhythms?

For LED flashlights and headlamps, a lot depends on the context and purpose of use. If someone uses them long enough before going to bed (perhaps only in the winter months when it gets dark early) then their parameters don't matter so much. Night shift work lights are also a chapter in themselves. Cool or neutral shades of white can help workers to stay awake, but it is the night shift itself that is the negative for health. For rescue and search activities, warm white (about 3000 to 4000 K) can sometimes be preferable, as it provides better visibility in fog, rain and snowfall compared to cooler shades. However, even these chromaticity temperatures have a certain amount of shortwave radiation that can interfere with circadian rhythms.

In all other cases, the use of more environmentally friendly LED flashlights can at least be considered. At the very least, the aforementioned colour „warm white“, which is a little more pleasant to the eye, may be preferred. Many models, especially among headlamps, also offer a supplementary red light mode in addition to the main white light. While monochromatic red light may not be 100% comfortable or practical for everyone, it is guaranteed not to disrupt the circadian rhythms of humans and animals, which also means it does not tend to spook fish or wildlife or attract insects. It can be useful to use it in a tent or cottage right before bedtime, for example.

A completely new feature is the special model of the Fenix Vitae headlamp, which was purposefully designed according to Hynek Medřický's patents specifically with circadian rhythm and healthier sleeping patterns in mind. Each time you turn it on, it first lights up with a weaker red-orange light that does not interfere with melatonin production. If the user just needs a little better illumination, they can switch to a very warm white light with a 1800 K chromaticity temperature (color temperature of fire) without blue, cyan and green spectral components. With an output of up to 600 lumens, the Fenix Vitae thus provides a solid beam of gentle light, which is currently unmatched on the market. When removed from the straps, it can also be used as a classic handheld flashlight if desired.

Left: First step, Right: second step