Glare never helps visibility, yet it is much too common. Some people actually believe that there isn't any light unless there is glare, because we are so used to seeing only bad lighting with its associated glare. Light trespass is someone else's light that bothers you. Clutter, confusing, and trashy looking nighttime lighting is a result of too much bad lighting. Energy waste is due to wasted light and to inefficient lighting sources.
Light pollution is the urban sky glow above any city, hiding our view of the universe.
Sometimes light pollution may be used as a term to cover all these adverse effects. People usually put in lighting for a purpose. It is a fact however that very few know anything about good lighting, and so they end up with a bad design. Mention the Resources available. Another type of poor lighting fixture.