Light pollution, also known as photo pollution, is the presence of anthropogenic and artificial light in the night environment. It is exacerbated by excessive, misdirected or obtrusive uses of light, but even carefully used light fundamentally alters natural conditions. As a major side-effect of urbanization, it is blamed for compromising health, disrupting ecosystems and spoiling aesthetic environments.

Description sourced from Wikipedia. Image sourced from TakePart.