If anyone is interested, here is a link that shows the manufacture of a camera lens, from the making of the glass to the completed lens. You will need a high speed connection, movie is via a flash player.
Canon Lens Construction
After seeing this, it makes one realize where the high cost can come from.
Also, the site has detailed technical links to all of Canon's equipment, old and new.
You Nikon folks can watch it to. Pretty sure that both processes are pretty much the same.
Enjoy