Impact of light

When we speak of light, we normally mean daylight. Natural sunlight is always present in varying colours and intensities, behind thunderclouds, in fog, in the stimulating morning light and in the soothing, warm colours of sunsets. Although we may not realise it, light has a significant influence on many processes inside our bodies. The reason is that it regulates the production of various hormones including the sleep hormone melatonin, which ensures that we relax in the evening and encourages us to fall into a refreshing sleep.

But what about those among us who, due to their occupation for example, spend little time outdoors and aren't exposed to natural daylight. For these people, and of course those who appreciate good working light, LUCTRA® has revolutionised lighting.

The scientific evidence

A clinical study led by sleep researcher Dr. Dieter Kunz at the St. Hedwig hospital in Berlin has provided evidence that LUCTRA® lamps have a biological effect on the production of the hormone melatonin. LUCTRA® is the first workplace lamp for which such systematic evidence has been established.

The study was conducted in July and August 2014 with 16 participants. During the test period, the participants were each exposed on five evenings to one of five different lighting scenarios. The biological effectiveness of the lighting was measured on the basis of the melatonin content in their saliva. In medicine, the sleep hormone melatonin is currently recognised as the most reliable indicator of the influence of light on human beings. In addition to saliva samples, the participants gave assessments of the visual comfort of the various lighting scenarios.

The complete study is available for download:


Night owl or morning lark?

Everyone has a personal daily rhythm which is “circadian”, meaning that it is roughly synchronised with day and night. We all know people who are already full of energy early in the morning, while others need a pick-me-up to start their day. And we are all familiar with the consequences of a disrupted circadian rhythm.

Follow your rhythm

The effect of a disrupted circadian rhythm becomes particularly obvious in the case of jet lag, when our body is forced to switch abruptly to a different day-and-night rhythm. Insomnia, irritability and lack of concentration are some of the immediate consequences.

More serious, however, is the effect of social jet lag, which is caused by continuously living against our internal clock. The long-term consequences may be severe to the extent of leading to depression or diabetes.

The total effect of light in one lamp

Modern LED lighting almost completely covers the colour spectrum of sunlight. That means that such light sources can have a stabilising effect on our biological rhythm, providing the body with light signals which set its internal clock even in an indoor environment.


Brightness alone is not enough

Illumination and light quality are vital for workers, especially in an office environment. A survey revealed that more than 60 per cent prefer light intensities in excess of 800 lux. Employees are more content and see themselves as having a higher level of wellbeing when they are able to individually adjust the lighting.

This includes the light intensity as well as the variable colour temperature – the alternation between neutral (cold white) and warmer (warm white) light. All lamps in the LUCTRA® range deliver light intensities of 1,000 lux and a colour spectrum between 2,700 and 6,500 Kelvin. The VITACORE® electronics  make it very easy to use and control these functions.

In addition to personal perception of the quality of workplace lighting, there are a number of statutory regulations. Here, flexible office concepts present the greatest challenge. Both the DIN EN 12464-1 and the ASR 3.4 standards lay down the requirements for an office workplace. By comparison to the preferred light intensity of 800 lux, workplaces should be illuminated with a minimum of 500 lux to comply with the DIN standard. Particularly demanding visual tasks sometimes require up to 750 lux. The lighting requirements in the immediate surrounding area are even lower with a minimum illuminance of 300 lux.