From my own experience with double vision (I could not look left, right or straight ahead, only straight down at the floor) the only thing that will help you with this, is strabismus surgery. Of ALL the surgical procedures I have had with TED, the strabismus surgery was the very very very best! And easy.
My surgeons and neuro ophthalmologists wanted nothing to do with radiation, did not prescribe it for anything, and felt negative about it. I can’t give you any reasons. But in any case, it was never suggested for double vision.
Of ALL the terrible things about TED for me, the diplopia (double vision) was the most stressful. I felt bonkers with it, and not safe, and I could not look at people. I had to speak to them while looking straight down at my shoes! I had immediate relief, and had mono vision after that surgery. I DO now have prisms ground into each of my lens of my glasses, simply because I can see better. But have not had any more issues with double vision.
Write back if you have questions.
Shirley