I did a search and it seems like it's an issue with some Dominator HD goggles. Have a look here.
At the end of the first page in thread you can see (what I presume is) an official Fatshark post: "Please contact support if your left/right is swapped. Some units boot up swapped due to instability which was fixed on a later driver f/w update."
Judging from that, if you contact Fatshark I'm sure they will be able to help you solve it.