Blue Outline Bug?

So just recently I've had this weird blue outline appear around the edge of  each eye view for no obvious reason. Its not always there and seems to move and depending on the orientation of the headset. It also appears more prominently in the mirror view generated on the desktop. I cant figure out where it came from or why its there as I haven't really changed much since it was working without it. certainly nothing within the oculus API. Was something changed?