光害
Light pollution is the presence of unwanted, inappropriate, or excessive artificial lighting. In a descriptive sense light pollution refers to any poorly implemented lighting, during the day or night, and can be found as an issue throughout the levels of our societies. Impacting all the way from the individual level, such as from an unwanted blinking light on a consumer product, to a community level, like a new urban development impacting existing communities from poorly planned street lights. Light pollution can also be understood as a phenomenon that refers not only to a specific source of pollution, but to the wider collective impact of intersecting sources of pollution.