Light it right
Several countries have begun to introduce rules to control outdoor lighting including Chile, Australia, Canada, Greece, Italy and the Czech Republic. The town of Bisei in Okayama prefecture was the first in Japan to introduce curbs through a 1989 ordinance. In the US, several states, towns and major cities have introduced anti-light pollution laws.
Measures adopted in various urban centres include:
Shading outdoor lights Requiring external fixtures to be shielded to prevent wasteful upward light distribution and glare intruding into adjacent properties, with illumination contained to the target area as far as possible.
Time restrictions Requiring non-essential lighting (including display signs) to be switched off after business hours, leaving only lights needed for security.
Bans on uplighting Some towns require all externally lit signs, displays, building and aesthetic lighting to be installed at the top and directed downward.
Curbs on projected light Where search lights, spotlights or lasers are continuously used outdoors, they may not be projected above a horizontal plane.
Sources: UK Select Committee on Science and Technology Seventh Report, Wired