That means saving energy has no any mean also that means limited petrol and natural resources have no mean either.Dirty lighting includes each kind of ineffective.
Main of them are such as;
Lighting attack ( light overflow) ; means unnecessary place lighting.
Eye dazzle ; means when it gives more light than usual,it can be dangerous for eye.
Upright Light ; means goes directly to sky and lost in space.
Extreme Light ; means much more using than necessary light.
The main sources of dirty lighting are the overflow parts of street or road lighting,parks,sports areas lighting,bill boards and buildings outside parts.
What is correct lighting ?
The easy answer is :
i-To privent way of light from the sky and turn towards correct way.
ii-To stop unnecessary lights at midnight such as advertisement or notice boards.