Recommendations for good lighting

The various effects of visible light lead to recommendations that should be taken into account when selecting lighting for different areas.

As a general rule: Light bulbs used for general lighting should belong to the free group (RG 0) or Riskgroup 1.

Lighting depends on the purpose

The lighting should be appropriate for the purpose:

• Whether in the office or in factory halls, different lighting requirement than in residential homes apply.
• In living spaces, where artificial lighting is used mainly in the evening, lighting with a lower blue component is advantageous.

Blue light component

Pay attention to the blue light component. The lower the colour temperature in Kelvin (K), the lower the blue light component. The release of the "sleep hormone" melatonin is inhibited by blue light in particular. During the day, blue light is desirable. But in the evening and at night, when the body needs to go into rest, it is usually not.

For classification: The colour temperature of candlelight is approx. 1,800 K, morning sunlight, approx. 3000–4000 K, and midday sun, approx. 5000–6000 K. The highest colour temperature is reached by the blue sky (> 10,000 K) because of the strong scattering of blue light in the atmosphere.

With many computer screens, laptops, tablets, and smart phones, the blue light component can be reduced by setting the option "blue light filter" or "night mode".

However, studies with different displays showed no evidence of a blue light hazard to the retina (i.e. photochemical damage to the retina or the retinal pigment epithelium (RPE)) as a result of exposure to high-energy light.

Lighting in your child's room

Take caution in your child’s room. The lens of children’s eyes is much more permeable to short-wave light. More high-energy light reaches the retina of children than the retinal of adults. Light fixtures should be positioned in such a way that small children in particular cannot look directly into them from a short distance.

Caution is also advised with toys that contain bright lights. This is especially true for bright, blue LEDs, especially because children may deliberately look into them from a short distance.

Lighting for living spaces

What applies to children's rooms also applies to all living spaces. Light fixtures should be mounted so that it is not possible to look directly into the light source from a short distance. The manufacturer's instructions for mounting light fixtures should therefore be followed.

Wall and table lamps should generally be less bright than ceiling lamps because they are more likely to have a direct line of sight, and the distance to the light fixture is usually shorter.

Frosted light bulbs are preferable to clear, translucent ones – especially because the risk of being blinded is lower.

For LED panels, the individual LEDs should not be visible as bright point sources. This also reduces the risk of being blinded.