Hi,

If your lenses are being subject to continuous condensation, you may have to worry more than just lens fungas, moisture can collect and cause rust on any metal parts too.
Fungus can appear anywhere on the lens surface and will look like a fog or little crystal
webbing, that doesn't go away, after they have been dried out.
Moisture causes the fungas!
If you do notice any fungas on your lens it is best to get to taken care of ASAP before
it starts etching into the coating and the glass!

Carol