Invisibible

I am having an issue in the Nether. Idk what causes it and it seems to be random. It's not too bad, since I can just exit the game and it fixes itself. However, it is very very annoying. The world suddenly becomes see through, except lava and mobs. I can interact with the invisible blocks, and run into them. I am not very tech savvy. I'm trying to add a screen shot, but it's saying something about a token.