Until the 19th Century, people only used the full moon, torches and simple lanterns to see at night. With the advent of gas and later electricity, night lighting has become more permanent and widespread, with the result that light pollution has slowly emerged. Light pollution can be defined as any modification of the natural light environment, especially that which causes some sort of nuisance. The most well-known forms of light pollution include sky glow, light trespass and glare. There are multiple consequences to this type of pollution, ranging from urbanization of the nocturnal landscape to loss of vision at night, or even the uncoupling of ecosystems.