In a broader context, light pollution deprives everyone of the joys of seeing a sparkling night sky. The glare that results from light shining sideways or upwards can be annoying and potentially hazardous to both car drivers and airline pilots. Glare can be avoided by using properly designed light fixtures. Light trespass is not only a bother and an inconvenience, it can actually interfere with other people's activities and use and enjoyment of property. In many cases, simply drawing the curtains or shutting the blinds would be an answer, but usually the problem could have been avoided in the first place through good lighting design and proper shielding.
Light pollution is also a sign of waste.
There is no benefit from lighting up the sky. In an effort to make the most efficient use of energy, Ontario Hydro is promoting the Power Saver Street-Smart Lighting Program to its municipal customers. This program offers municipalities financial incentives to convert their current inefficient street lighting to high or low pressure sodium fixtures including the installation of full cut-off shields to reduce light pollution. Call your local Ontario Hydro office for further information on the Power Saver Street-Smart Lighting program.