To translate optical technologies in synthetic material requires a high degree of precision in terms of mechanical engineering, tool or process engineering, in combination with a high degree of reproducibility and cleanliness of the production environment. Even smallest component defects or deficiencies such as fisheyes, silver streaks or flow marks will mean outright reject. Hence, the processing contractor has inevitably to be in possession of the required product, process or production know-how at highest levels. Determining process-relevant parameters or their tolerance limits and to establish permanent quality control for the products to be produced are very complex and costly challenges. In a word, the optical sector makes highest demands.