The image shows a mob grinder I'm part-way through building that farms, among other drops, enderpearls.
One problem I have encountered with the design is that sunlight can enter through the glass walls, causing endermen to teleport out of the tower. This reduces the efficiency of the grinder during the day as well as filling my house with endermen.
I want to keep the windows if possible and I was wondering, does FTB offer any blocks that look similar to glass that will block sunlight? (Stained glass, hardened glass, reinforced glass, one-way glass etc. etc.)