"Perfect" glass is a relatively modern concept in photography. It seems to coincide with multicoating.
As Andrew wrote, it takes a pretty substantial issue to show up in the image. I recall seeing a website quite a few years ago where a cracked (35mm) lens was tested. http://kurtmunger.com/dirty_lens_articleid35.html
So, I wouldn't worry a out this.
And, sometimes it can work in your favour: I bought a 14" Verito that has 3 tiny chips in the rear glass for $150. It's a soft focus lens FFS.