I just used glass block windows in a bath and they work great. They insulate better than regular windows, and you can get blocks with various levels of privacy. During the day you get more light from glass block windows with no curtains than from regular windows that have privacy curtains. It's a cleaner look as well with no curtains.
Check out this web site below for various styles:
You can get acrylic blocks that are light weight and easy to use. I used glass block windows that were made to a size that I specified. The shop mortared them together into a single unit with steel reinforcing rods in the joints and I mounted them in the window opening.