The community of Durango, Colorado has completed replacement of all of its street lights to keep light from shining up into the night sky. This is part of an initiative to be dark sky compliant - to prevent light pollution and contribute to a more natural evening environment. See Stargazers Look Up.
The “full cut-off lenses,” which replace traditional teardrop-shaped bulbs, shine down and not out, and are meant to save on energy costs, reduce light pollution and limit the impacts of artificial light on wildlife.
