Melanopically effective lighting can also support human circadian rhythms at indus-trial work premises. Dynamic lighting with non-visual effects has an energising impact in the morning and at mid-day and makes for a better night’s sleep.

Many people in industry work shifts, having to get up, for example, very early in the morning. They often complain of sleeping badly and being tired during the day. The result is lower productivity, because work-ers who cannot regenerate overnight are not very efficient during the day. As an Austrian study in 2010 showed, biologically effective light helps.

Greater sense of wellbeing, better concentration
The research team chose two dynamic lighting scenarios for the general lighting: in both cases, illuminance varied from the standard 1,000 lux to a biologically effec-tive 2,000 lux at a colour temperature of 4,000 kelvin. In the first test set-up, the doubling of the lighting level was clearly perceptible and implemented at longish in-tervals so that the lighting had an activat-ing effect at the beginning of a shift and a relaxing effect at the end. In an alternative set-up, the researchers introduced an im-perceptible dynamic brightness cycle with shorter intervals. The findings show the positive impacts of dynamic room lighting with non-visual effects

•  significantly better quality of sleep
• greater sense of wellbeing during and after shift work
•  faster performance of assigned tasks.

Shorter cycles also work
In a lab experiment involving 29 test per-sons, a programme was then run – also in 2010 – to see if dynamic lighting with a bi-ologically effective colour temperature of 4,000 kelvin also works if the sequence is speeded up. This type of dynamic lighting entails comparatively little expense be-cause the illuminance varies and is not kept at a constant high level for long peri-ods of time.

The lab study showed that light which gradually increases from 500 to 2,000 lux and is then imperceptibly lowered to its original level reduces physiological re-sponses to stress. More research needs to be done in this area.

One thing is certain: biologically effective lighting demonstrably improves quality of sleep, so employees are more active and motivated during the day. An optimal light-ing level and melanopic lighting are good for employees’ health and help maintain their productivity.