Is this swelling or lid retraction? Three months post orbital decompression. (photos)

It is likely eyelid retraction as swelling doesn't persist this long after surgery but best to see an oculoplastic surgeon for evaluation. See following link too.

The photos don't suggest that you have swelling but it is possible to have some degree of persistent swelling even 3 months after an orbital decompression surgery.  It is very hard to make the position of the two eyes perfectly symmetric. In the photos, there is still trace left upper eyelid retraction.  The position of the right upper eyelid looks good.  The lower eyelids are a bit low.  The principle reason for repositioning the lower eyelids would be to manage dry eye.  You would also get some aesthetic benefit. Some might advocate additional orbital decompression here but recognize there will always be differences in opinion regarding how best to manage your overall rehabilitation. Generally it is helpful to have inferior orbital rim augmentation in these cases.  Some surgeons try to avoid using a spacer graft in these lower eyelid.  Having done over a thousand lower eyelid reconstructions, I think this micro trend is corner cutting for busy surgeons and not helpful for eyelids and their owners.  I think these reconstructions do very much benefit from a lower eyelid spacer graft.  Note the video attached takes about lower eyelid retraction after blepharoplasty but the approach is the same for fixing lower eyelid retraction after orbital decompression.

Hi,
If you are not seeing any improvement since the eyelid surgery then you may have eyelid retraction.  If things are still continuing to improve or change then I would wait until you are stable. Thyroid eye/orbital surgery is often a staged process after decompression and residual eyelid retraction can be addressed. Good luck.