Sometimes, once an orbital decompression has been performed, it causes the eyelids to retract more than they were before. Because the eyelid is pulling back, it makes the eyes appear bigger.
Most times, bony decompression is done first (the orbital decompression you refer to), the second surgery is often strabismus surgery to correct double vision if needed, the third surgery corrects eyelid retraction.
Three weeks isn't a whole lot of time post surgery. I remember I was a mess for a few weeks after the decompression and for several weeks after the second surgery (lots of swelling for that one!).
Call you doctor if you are really concerned. Hopefully, it is nothing or just the normal eyelid retraction looking worse to you.
And, the last piece of advice I have for you (and I wouldn't have wanted to hear it when I was going through the whole deal, so take it for what it is worth) - this Thyroid Eye Disease requires much patience. There is no cure, just several steps that need to work themselves out over time. There is no magic cure, just time and a good eye doctor.
Good luck to you.
WOW! Would you explain this thyroid eye disease..Did you have hyper thyroid..Did you go to an eye dr...Did you have graves disease also