[Leica] impurities in lens

[Chris Lee <chrislee@mac.com>]

I went to a local Leica dealer today where I was looking at many of their
lenses. I noticed many of the lenses, which were supposed to be brand new,
showed some very tiny "impurities" in the glass. These looked like very fine
particles suspended inside the glass elements. Although they were only
visible at certain angles in very strong lighting, I couldn't help but
wonder what they were. Can someone tell me if these lenses are defective? Or
these things are supposed to exist in every lens, good or bad?

Regards,

Chris