Lights off: Environmental safeguard or business hazard?

(CNN) -- From Las Vegas to New York, the night sky in many U.S. cities is beginning to look like daylight. Many say that's causing harm to people and the environment. The issue has sparked a heated battle in several states that view destructive ambient light at night as a growing problem, especially for astronomers and other scientists trying to study the night sky. Ambient light is a major issue in Tucson, Arizona, home of the National Optical Astronomy Observatory. The city has fought to cut back on light pollution, but many industry leaders say that light restrictions could do more harm than good.

David Crawford, executive director of the International Dark Sky Association, discusses some of the effects of ambient light, and ways to reduce what he terms "light pollution," with Natalie Pawelski. And Don Dybus, vice president of real estate and public affairs for Clear Channel Outdoor, discusses reasons why light pollution concerns need to be balanced with the business community's needs.

Light pollution debate: David Crawford

Light pollution debate: Don Dybus