>>2992503Shine a light through the lens and look through it at different angles. Lens fungus normally manifests itself as spots, a pale haze, or web like network.
Generally speaking, if there's dust in the lens then there's a greater chance that fungus could grow there. Lenses straight out of the factory are relatively sterile inside and fungus can't grow in conditions such as those; but the addition of organic material like dust (The type you have in your house, not the type in the desert) can give fungus something to feed off of and allow it to get enough to grow from.
