Actually during Special Operations Warfare training it's taught to pilots & other soldiers who have to wear a helmet/mask to use "HUMAN PEE, note only HUMAN pee will work" on the inside of their mask. This creates a great seal and does not allow the lens to fog up.
This has been well proven during combat operations that human pee works great to stop the fog on pilot lenses as well as other types of lenses used by the military. Experiments with dog, cat, and horse pee didn't work so remember to pee on your own lens before you take off guys.
Next time try PEE and then let us all know how it turns out.
Actually just joking,,, hopefully no one believed me!!!!
There is a spray agent (anti fog) especially made for the helmet visor. I am actually using one and it works really well even riding at freezing temp. As for the rain lumps (rain beads) on the helmet visor there is also a spray agent to beads out rain drops on the visor. This is manufactured by yamaha. I have both these. They are really helpful. I wanted to share pictures so I could give you better a better idea but im kinda lost how to upload/insert images.
Good morning! Here are the products I am talking about. Although The label is written in Japanese. "Antifog spray" and "shield water repellent". I hope there is one available in the market. a little pricey but it will keep your visibility clear and safe riding as well. Try online it might help.