'fungus'

[rbbblues]

is there really such a thing as fungus growing within the elements of a lens?????

[robertwgross]

The fungus does not grow within a piece of glass, but it can grow on the surface or coating of one or more elements within the assembly.

---Bob Gross---

[Simon Spiers]

is there really such a thing as fungus growing within the elements of a lens?????
Take a look at this rbbblues.
http://www.photoquack.de/tutorials/mushroom.htm