Can I polish the windshield instead of replacing?

In the case where the scratches and abrasions on the glass are small, the polishing can bring back the windshield to its former transparency. And it will be cheaper. But when the scratches are big, will have to grind it to polish - in this case is removed from the glass with a small layer using a special machine. Uniformly with respect to remove this layer can not be almost never, and in light of the opposing headlights so the glass will blikovat. In addition, grinding and subsequent polishing is sometimes more expensive than the cost of new glasses.