When I worked I had to occasionally use self contained breathing apparatus which had a tendency to fog. The guys who maintained the gear found some stuff to spray on the inside of the visor to prevent it. Just had a quick search on the net & they sell something similar for motorbike helmet visors, wonder if that would help?
RonA
You can buy the expensive anti mist sprays but there's a much cheaper option. A tiny spot of fairy liquid smeared on the inside of the visor and then polished off with a tissue.
I have tried several different types of eye protection including some expensive bolle stuff. But every one steams up when I use them with a dust mask. The only thing that works for me is a full face shield & I use that 90% of the time.