People often ask me what they can do to stop light pollution, and one easy answer is to only buy "dark sky friendly" lights for your house. By that I mean lights that are shielded so that they can only shine downward--not into the sky, into our eyes, into our neighbors' house. Unfortunately, buying shielded lights for your house is more difficult than it should be. Or rather, it is waaaaaaaaaaaaaaaaaaaaay easier to buy unshielded lights.
Yesterday at Home Depot, I counted 89 outdoor light fixtures. Of those, four were shielded. When I was a teenager I was at the U of Minnesota football game where Nebraska beat the Gophers 84-13, and I got up and walked around during the second half because I was so depressed. At Home Depot, the score was 85-4.
Most of the 85 unshielded lights are what we call "brass and glass" fixtures, and we buy them because they look good during the day (i.e. on display at HD). But at night they spray light in all directions. Their designs are modeled after fixtures intended for much, much, much dimmer gaslight, rather than electric light. There do exist classic designs such as these but with no glass and with the lamp up inside the fixture so that light only goes downward. But Home Depot does not carry any of these.
Also, Home Depot (and Lowe's, and probably every other American home improvement story) continues to sell unshielded "security lights" that blast light in all directions from dusk to dawn. I saw no shielded "security lights" (some of my friends call them "insecurity lights").
The thing is, light at night is not the problem--the way we use light at night is the problem. Shooting light in all directions does not make any of us any safer, and in fact it contributes to making the night more dangerous by blinding us, casting shadows, and giving the ILLUSION of safety. Not to mention wasting a ton of energy and money.
I love working with the problem of light pollution because it is so within our grasp to solve. If we were to shield our lights, we would make a huge dent in the problem. But it sure would help if we had better choices when we went shopping for lights.