X-ray vision by just walking around in world

I was going down in my mine shaft when i was walking to find a spot to mine. Suddenly no blocks were visible. All enemies, lava, water, and light from torches were still visible. I closed out of the window and reopened and i still had the issue. I even restarted my Windows computer and opened the program and it played fine for about 5 min and then did the same thing.