Light blocker and diffusor functions have a wide range of areas of application in technical plastics. Along with the automotive industry, such solutions for modification of light radiation are used most of all in medical technology and pharmacy. The important thing here is always the highest precision in conditioning plastics. In medical technology and pharmacy, especially, light blockers help to assure that solutions and medications are protected from the effects of light and that their functions and effects are preserved. For the automotive industry, we develop day and night solutions with the help of diffusors that allow a light source not merely to radiate as beams but scatter the light over the entire surface. Implementing such complex requirements is the specialisation of the Treffert corporate group, which develops solutions for each use case in its own laboratory.