Fur around eyes slightly matted?

I've noticed on two of my girls that there is a small amount of slightly matted fur around one of both chins' eyes. They are not housed together. They dust bathe in Blue Cloud dust 2-3x per week. There is no wetness or anything, and actually I think it's not all that noticeable, only I'm always looking at them so I notice I guess.

I'm planning a vet visit (check up) soon for these guys, but I'm wondering if there is something I can do in the interim for them, or if this is just something that happens with some chins or something.

Thanks in advance.