Glass work is always a feast for the eyes, especially when it is hot glass. Watch as a Nikkor lens is made from beginning to end. It is wonderful to see the care taken to search by eye for defects, refraction issues, clarity etc. It may just be for the video, but it seems that the workers truly do take pride in their product.
What I found somewhat surprising was the amount of work that went into refining the glass BEFORE it was even put into a lens mold. I would have assumed that much of the work would have come after.