Healthy light full spectrum

What constitutes healthy light and how you can use it for yourself

LEDs have no longer been a rarity in private households since the early 2010s. Often reviled at the beginning, the energy-efficient light sources have been continuously developed over the years so that not only their efficiency and service life have improved. The choice of light colors and color temperatures has also increased.

A more recent achievement followed around 10 years later: 2018 was the year of full-spectrum LEDs. They are designed to illuminate interiors with the quality of daylight. Sounds good at first. But the light sources also have disadvantages. Due to their higher costs and shorter service life, they have not yet been able to establish themselves on the market. But something is happening. Full spectrum LEDs are becoming cheaper. And they are said to have health benefits. At least that is what basic research in this field shows.

What is full spectrum light?

Difference between sunlight spectrum and full spectrum LED and standard LED

The spectral composition of daylight has shaped human perception for millions of years. Full spectrum LEDs imitate this spectrum. This is intended to create particularly natural-looking light - or light similar to sunlight.

The light from full spectrum lamps is therefore very similar to that of the sun. Why? Because, like sunlight, it is produced using the seven colors of the rainbow. In addition, the light with its low infrared components comes very close to daylight. This is one reason why lighting with full-spectrum LEDs is often referred to as natural light or true light.

Research into the effect of sunlight

There is no question about it: Humans need sunlight. Not necessarily to survive - we could live in a dark bunker for years - but to lead a healthy life. After all, the sun is responsible for our sleep-wake cycle, promotes the production of vitamin D in our skin and even strengthens our immune system. Researchers at Georgetown University Medical Center discovered this in 2017.

Their findings: A small amount of blue light, which is found in the sun's rays, triggers the so-called T-cells, move faster - This human cell therefore reacts to sunlight.

Phase (561 nm) and Fluo-4 fluorescence (488 nm, average 2.7 mW cm-2, 37 °C) images of a Jurkat cell show light-induced increase in intracellular [Ca2+] followed by extension of lamellipodia. Scale bar = 10 μm. Source: https://www.nature.com/...

Gerard Ahren, lead author of the study, says: "T cells, whether helper or killer cells, need to move to do their job. This is the only way they can get to the site of an infection and initiate a response. The study shows that sunlight directly activates important immune cells by increasing their movement."

(original:) "T cells, whether they are helper or killer, need to move to do their work, which is to get to the site of an infection and orchestrate a response. This study shows that sunlight directly activates key immune cells by increasing their movement."

Study on the effect of full spectrum light

If you go one step further, you could therefore assume that full-spectrum light, which is modeled on sunlight, is beneficial to health. There is currently hardly any research on this - not even basic research. However, a study by the Frauenhofer IBO could be a first step. Here the the influence of full-spectrum LEDs on visual perception and performance was investigated.

Assignment of the sky conditions to the color temperatures (left) and the relative spectral radiant power of selected illuminants of the daylight D standard (right). Image: Fraunhofer IBP

The study involved 83 test subjects in an office-like room environment. Each subject completed tests for around one hour in one of four randomly assigned lighting situations. The perception and effect of two full-spectrum LEDs and two standard LEDs were compared. One of the results: In all LED conditions, subjects felt more alert and attentive at the end of the test session than at the beginning. However, no difference was found between the four LED variants.

However, this does not mean that the full-spectrum LEDs performed the same overall in the study as the conventional LEDs. In the subjective evaluation of naturalness and comfort, the full-spectrum LEDs produced better results than the standard LEDs. A reason to conduct further research here. And perhaps to give preference to full-spectrum LEDs in future.

What are the advantages of full-spectrum lighting?

What can be deduced from the research to date? Not much yet. But there are some assumptions that require further research. For example, the light color of full-spectrum luminaires - just like real sunlight - could have a vitalizing effect. The light could also provide more relaxed vision at work, prevent headaches, improve well-being and even prevent winter depression. This is one reason why advocates of full-spectrum LEDs describe their light as the best artificial light on the market.

Bring the brightness of the sun into your home or office

What can we say? Research into the effects of full-spectrum light on human perception shows that full-spectrum LEDs have advantages over conventional LEDs.

So you could bring the benefits of sunlight into your home with appropriate LEDs. Even if there is not yet enough research on the subject, it is worth a try. Especially in offices and other workplaces where people are still exposed to fluorescent tubes, replacing the light sources with lamps that emit light close to the sun could be considered.

The incandescent bulb has long since been replaced by LEDs. Is it now time to replace conventional LEDs with full-spectrum lamps? We at Lichtblock say: yes.

Our healthy, flicker-free light sources with full spectrum are already in development and will probably appear in the store in early/mid-2025. If you are interested in this topic, please here in our newsletter here!