Until the late 1990’s, lighting recommendations have been based entirely upon achieving safe visibility for the task at hand. These days more and more factors are being taken into consideration. These encompass human needs, aesthetics and with increasing raw material and energy prices, economic constraints.
In a country which has adopted a 24 hour culture with high demands on aesthetics and public safety, artificial light is a dominant feature of the night. Add to this the number of offices and other indoor workplaces which do not maximise on utilising natural light, the end result is an increase in health issues through psychological and physical symptoms caused by flicker, the de-synchronisation of circadian rhythms and an amplified carbon footprint.
Several aspects of electric lighting may affect health. These include low-frequency magnetic fields, ultra-violet emissions, glare and variation in luminous intensity, both that appears as flicker and that which is too rapid to be seen.
The average office environment illuminated to 500 lux horizontal at the working plane using a white light source is more than sufficient for the visual system to process information but is barely adequate to stimulate the circadian system. Anyone who spends the majority of their time within a building is being subjected to illuminance comparative to a state of continual dusk. This in turn does not fully suppress melatonin production affecting the general emotional state of those who are subjected to these conditions.