| Class 0: |
no filter effect |
| Class 1: |
little glare protection, 43 – 80 % light transmissibility, adequate for little sun, cloudy conditions or at dusk |
| Class 2: |
medium glare protection, 18 – 43 % light transmissibility, adequate for more sun and the daily use in Central Europe |
| Class 3: |
strong glare protection, 8 – 18 % light transmissibility, adequate for holidays, mountains and beaches as well as Southern Europe‘s sun intensity |
| Class 4: |
extreme glare protection, adequate for glaciers, inadequate for driving |
