How does lighting affect my child?

Which lights are best for learning?

Significant amounts of government funding are presently being allocated to schools switching over to energy-efficient lighting systems (i.e. LEDs) and the lighting industry is actively promoting blue-enriched white lighting as boosting concentration and alertness. The question arises: Is concentration the only factor to take into consideration in a healthy learning environment? Is it in the children’s best interest to manipulate lighting to increase attentiveness and performance? Do we know enough about modern lighting technology to be using it in schools?

Opinions about lighting in schools can be biased and one sided. However, it is widely accepted that long and short-term memory are influenced by external conditions and that people of different ages have different lighting needs.

Dr. Uwe Geier from WirkSensorik GmbH has examined the effects of the quality of light on students and their study habits. In his first experiments at various schools and kindergartens, he studied the effects of different types of lighting on tasks such as reciting, dictating (spelling) and painting.

To further explore and research these effects, we offer consulting, workshops and awareness training sessions for colleges in schools and kindergartens, where participants can experience how different types of artificial lighting affect the human constitution. For more information, contact Ulrike Wendt.

Light in Schools

Despite medical reports confirming risks to eye health and sleep disturbances directly resulting from blue-enriched lighting, LEDs are being promoted as a promising light source for students in schools.1

This stems from the fact that bright light is known to increases alertness. LEDs can be extremely bright with little power consumption. However, such light is only possible with high percentage of blue light in white LEDs, which is a stimulant. With bulbs that are just as bright as an LED, there is more blue light in LED than in halogen or incandescent bulbs (see Terminology).

Experiment: Extreme Example

This Hamburg school experiment that was carried out a few years ago in cooperation with a lamp manufacturer.2

Teachers were instructed to increase brightness and blue light to control students’ concentration in class. Teachers reported students reading faster with more blue light. At the same time, children moved much more in class and their levels of cortisol, a stress hormone rose. The experiment was stopped because the teachers continually aimed for optimum concentration and parents complained about behavioural disturbances in their children after class.3

A recent example of the impact of the blue light factor in LED light on young adult students is described in the study by Oliver Keis and colleagues. Under bright LEDs (5500 K, the Hamburg experiment only used 12000 K!), the concentration and performance levels of 19-year-old (predominantly male) vocational students improved when compared to the levels under fluorescent lighting. However, not in all areas, memory ability remained the same under both conditions. When the students were asked which lighting they preferred, they chose the old fluorescent lighting. The experiments were conducted early in the morning. The author clearly recommends not using blue light in the evening as it causes sleep disturbances.

A study

entitled LED macht Schule sponsored by the German Ministry of Education is quoted regularly when speaking of the so-called benefits of LEDs in schools. When students in 33 schools transitioning to LEDs in the classrooms were asked about the new lighting, they said they had better grades with the LEDs. The old lighting consisted of fluorescent tubes, some were broken and dirty. In some schools, windows, floors, heating and ventilation systems were renovated at the same time as the lighting was changed. It is in fact impossible to assess which changes influenced the higher grades.

The information available raises some crucial questions:

  • Previous comparisons have been made so far usually between LED and fluorescent tubes. What are the results when halogen lamps similar to the daylight spectrum are compared to LEDs or fluorescent tubes?
  • Increased concentration due to a high blue content in the LED has been proven. However, how do these lights affect other important abilities, such as a child’s imagination or empathy? The previous studies offer no information in either of these areas.
  • Stimulation from high-energy blue light may be helpful at times for young adults, but what about children in kindergartens and elementary schools?

With these questions in mind, we conducted our study to research a wide range of children’s abilities, not just cognitive abilities. The initial results reveal clear effects of the LEDs, for example in the qualities of children’s drawings under incandescent and halogen lights. First results in English:

1 Oliver Keis and Colleagues: Influence of blue-enriched classroom lighting on students׳ cognitive performance. zurück nach oben
2 At the same time, Philips Lighting set up a triple circuit light switch in some schools in Hamburg Philips lighting and a study was carried out at the Eppendorf University Hospital. The results are not available on the internet. zurück nach oben
3 This trial has been successfully challenged in court for manipulation and physical harm to minors. However, this is often overlooked in the reports (rarely available on the internet, here in German):  or for a more balanced view (in German) - Schullicht. See ‘Dynamic Lighting for schools:
Complete documentation of the Hamburg experiment is available upon request. zurück nach oben



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