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.