One way Blocks

These blocks you are able to see through from one side, and the other side, they look like a different block; Stone, Obsidian, Regular Glass, Oak Logs, etc, most blocks would be able to be turned into this variant by combining them with Tinted glass, or regular glass if you wish to have a light source come out to the other side of the block.

There is many applications for this block in builds and i think it would a fun addition to the game.