Most of us live in urban areas, comprised of streets, homes, offices, parking lots and other buildings. We use artificial light to brighten our homes and path ways in the dark. Rarely do we see stars. Maybe only a handful of them, and they seem to be few and far between. We plan vacations around being in the openness of the desert, mountains and valleys to soak up the beauty of the world's natural nighttime light.
As civilizations arise into industrial societies, artificial light is necessary to live, work and play. However most of the lights are being used improperly, compromising both the night sky as well as other inhabitants of the wild. Birds rely on night for proper mating and hunting, and turtles are distracted by artificial light and don't hatch eggs properly. While the necessity and use of lights are not in question, their design most certainly is.
All cities have ordinances preventing the incorrect use and design of lights. However, we've still tried to find a house for the first time and the porch lights are illuminating the garage or a tree instead of the address. We've all had to squint from the glare produced by lights to see if someone was on the other side of the door, car, or tree because drastic shadows were preventing us from seeing someone instead of allowing us to see that person.
There is a solution to light pollution, angle lights down towards the path you wish to illuminate, and create shields from preventing the light shining on the sky.
The International Dark Sky Association is the only non-profit created to preserve and protect the nighttime skies through environmentally responsible outdoor lighting. It has created a program for communities, parks and reserves to aspire to be included in, for all who achieve this association are exceptional in their efforts of limiting light pollution.
For practical products and tips:
Guideline for Residencial Lighting.
Search approved fixtures.