Good for you!
The Late Empire isn't covered often enough, in my opinion.
Now here goes for Roman window glass:
http://www.metmuseum...gls/hd_rgls.htm
Glass windowpanes were first made in the early imperial period, and used most prominently in the public baths to prevent drafts. Because window glass in Rome was intended to provide insulation and security, rather than illumination or as a way of viewing the world outside, little, if any, attention was paid to making it perfectly transparent or of even thickness. Window glass could be either cast or blown. Cast panes were poured and rolled over flat, usually wooden molds laden with a layer of sand, and then ground or polished on one side. Blown panes were created by cutting and flattening a long cylinder of blown glass.
Here's a site with photos of Roman window glass:
http://www.romanglas...articles.htm#No
Bona Fortuna!