First of all, do it calmly and carefully; avoid rushing and trying to clean it while driving and without taking the necessary precautions.
For safety reasons, we do not recommend such operation. You also risk reducing the visibility and scratching the visor, for example when trying to clean it while wearing gloves, without realising that their seams have some parts that may irreparably ruin the surface.
Therefore, if you are driving and cannot keep going because of reduced visibility, stop as soon as possible and take the helmet off. Some of you might have thought ahead and included a pack of wet wipes suitable for cleaning helmets in your perfect motorcyclist kit. Otherwise, if you are near a café or a petrol station for a coffee break or to fill up, you may want to you use the lavatory to clean your visor.
Dampen the visor with water and pour a small amount of mild liquid soap onto a damp cloth or other non-abrasive fabric, then gently remove anything that should not be there! Next is the drying stage. It would be better not to use anything that may scratch the surface of the visor, especially if it’s coloured, as it is more delicate that a transparent surface in that case. Ideally you’d use a soft and clean microfibre cloth.
Once you’re back home, for optimal cleaning, you might consider disassembling the visor following the appropriate instructions. Proceed as above, but this time focus on cleaning those parts that normally cannot be reached, as they are very close to the fastening mechanism.