Light in man’s environment

Light in the form of solar radiation influenced early civilisations and resulted in the independent development of a number of sun-worshipping dieties. These were of particular importance as hunter gatherers transformed into settled agricultural societies. All artificial light sources were synonymous with fire, and early civilisations began to expand their visual day by burning brands, oil, and candles. Fire-based light sources extended for thousands of years and were still present in the era of gas lighting. Light meant fire risk. The advent of incandescent bulbs and the era of electric lighting really only expanded in the early part of the twentieth century. Fluorescent lighting became available in the 1940s, and today the drive for low energy has resulted in a plethora of novel light sources-in particular, light-emitting diodes (LEDs). Evolution governed the development of the eye in relation to roughly 12 h of light gradually changing to 12 h of darkness. Today almost daylight levels can be achieved abruptly at the flick of a switch. Many studies have demonstrated the spectral dependence of eye health, with the retinal hazard zone associated with wavelengths in the blue, peaking at 441 nm- many of today's low-energy sources peak in this region. Given the increased longevity and artificial light sources emitting at biologically unfriendly wavelengths, attention has to be directed towards light in man's environment as a risk factor in age-related ocular diseases

Voices for the darkness: online survey on public perceptions on light pollution as an environmental problem

Light pollution is increasingly affecting ecosystems and human health. We present results from an online survey aimed to chart what aspects of lighting are considered harmful and how light pollution is perceived by the public. We focus on affluent societies by using Finland as an example of a northern industrialised country. The survey generated 2053 responses, particularly from well-educated urban persons living in residential areas and interested in astronomy or environmental issues. The results show that the lighting of residential areas and lighting serving traffic are considered the most common sources of light pollution while commercial lighting is perceived as the most annoying form of light use. Respondents commonly considered light pollution as a disturbance for outdoor recreation and relaxation. The results suggest that the ecological and health effects of light pollution emphasised by the research are poorly known by the people emphasising the aesthetic aspects. The results indicate relatively wide but passive acceptance for policy measures aimed at reducing light pollution.peerReviewe