"We use the term 'light pollution' to cover the many different examples of society’s overuse and misuse of artificial light. Most of this light is electric, though increasingly it is electronic (think LEDs). Major elements include 'sky glow,' the luminous veil of light hanging over every city of any size; 'light trespass,' the light allowed to flood from one property to another—think of your neighbor’s light shining into your bedroom; and 'glare,' light allowed to shine directly into your eyes. The bad news is that the costs of all this light are high, and are just beginning to be discovered by scientists, ecologists, and others. Meanwhile, our world is brighter than ever before, and growing brighter every year."
"Once you begin to see light pollution, you see it everywhere, and you can think about how to control it. But the first step is to see the light around us."