In the dawnguard dlc gelebor said that the dwemmer made the snow elves blind. I know it was because they let the snow elves stay with them but I just wonder why they would make them blind. What did the dwarves get out of making them blind? Was there any reason for them to do that?

My guess is it was to keep them from knowing their secrets. Also, weren't the Falmer used for experimentation and slave labor? I could be wrong. I'm not big on the lore.