If you have a block under you such as sand or gravel since it can fall through you, you can then pish a piston through your head and you can kind of see through the world. Not major.
To reproduce,
1) Surround yourself with blocks (Any)
2) place a piece of sand above you.
3) Place one piston (Any) in front of you.
4) Place a redstone torch next to it to activate it.
This appears to be a duplicate of MC-101049, which hasn't yet been resolved. If you have any additional information to provide regarding this issue, feel free to comment on the parent ticket. If you feel that this issue is affecting you, feel free to vote for the duplicated ticket, to give Mojang a basic idea of how many people are impacted by the problem. Just to further inform you, this will not determine how quickly the bug gets handled or fixed.