What light pollution?
Light pollution is the excessive and prolonged use of artificial lights, in a way that results in the brightening of night skies, disrupting natural cycles and activities of wildlife, health problems in humans, as well as preventing humans from observing stars and other planets.
In other definitions, it does not only have to do with the sky but anywhere that artificial lights are used, where they are not intended to. Other terms often used for light pollution are ‘photo pollution’ and ‘luminous pollution’.
Note that this is not only a city center problem. There is also light pollution when you use too much light in your compound which affects the comfort and health of your neighbors. This could be your outdoor light‘s intrusion into other people’s bedrooms. This can be called a nuisance. Too much light indoors also is classified as indoor light pollution if it is wasteful and it has an effect on the health of people living in that room.