Light Pollution Light pollution, also known as luminous pollution, refers to a phenomena that excessive and obtrusive optical radiation seriously affects human activities of living and production. Actually, it is a byproduct of industrial civilization and its sources include building exterior and interior lighting, commercial properties, offices, factories, streetlights, electronic products and even papers. How is light pollution produced and how does it do harm to us? First, colorful neon signs, lighting of architectures and streetlights(some sources of light pollution) light up cities over night. They competes with starlight in the night sky for urban residents and interferes with astronomical observatories. Second, all kinds of lighting fixtures, glass buildings, electronic products and polished papers involve people in a world full of intense lights and harmful radiation. As a result, more and more people are suffering from myopia, night blindness, insomnia, neurasthenia, and even cancer. Thirdly, artificial daytime has broken the laws of nature and has hurt many creatures. It disrupts the growth mechanism of plants and makes nocturnal animals lose their facilities of distinguishing the orientation, then directly or indirectly causes their death or extinction. To prevent and control light pollution, we have to take some effective measures. For one thing, we can make full use of technology to improve our lighting fixtures to make them environmental friendly; for another, we should adjust our lifestyles of using lights and electronic products.