It's the multi-coating,,,
The multi-coating used on camera lenses (scope lenses?) is a gelatin substance.
Mold can and often does form on it,,,
You can clean it off but you will lose the anti-glare feature.
Nikon, Canon, and Minolta all used the same stuff,,,
This has been a known issue since the 80's.
Caje: The coward dies a thousand times, the brave only once.
Kirby: That's about all it takes, ain't it?
Combat: "A Silent Cry"
Aarond is good,,, Aarond is wise,,, Always trust Aarond! (most of the time)