What is longest lasting treatment for upper eyelid hollows?

Upper eyelid hollowness is a dramatically underappreciated, yet incredibly important component of aging in the eyelids. With normal aging, our upper eyelid fat pads tend to retract and expose this upper lid hollowness, those with “deep set eyes“ are especially prone, and unfortunately old-school upper eyelid surgery that is overly subtractive can artificially create this hollowness early, actually looking worse than it did before surgery - the before and after photo in the link below resulted from overly subtractive upper eyelid surgery with another surgeon, and you can see the results after revolumization of the upper lids. Correcting this hollowness can happen with fat or filler injections into very specific planes of the upper eyelid, or transposing and rearranging the upper eyelid fat pads to provide fullness, as you see in this surgeon’s view video, borrowing the excess fat to move into the areas lacking fullness!
To ensure you are receiving the highest level of care, seek out a modernly trained, new-school dermatologic surgeon, oculoplastic surgeon, facial plastic surgeon or plastic surgeon who is board certified and fellowship trained in one of these “core four” cosmetic specialties. Membership in organizations like the American Academy of Facial Plastic and Reconstructive Surgery help to identify a highly trained surgeon.
Cameron Chesnut
#realself100 Physician

Hyaluronic acid gel filler (Belotero or Restylane) is the best, safest treatment for upper eyelid hollowness. I have published on this and you can find manuscript on my website. Fat injection is an alternative option. See following link.

It is not accurate that it will only last a few months.  However, that does not completely address your issues.  You have not posted photographs but a double fold surgery that develops a triple fold is a failed double fold surgery.  Grafting fat is occasionally used to address these but this requires the eyelid to be completely reopened. Even without seeing your photos, I suspect that you are experiencing a PUBS-post upper blepharoplasty syndrome.  This includes ptosis, upper eyelid hollow, indistinct or absent upper eyelid crease.  If you had a single clean insertion of the upper eyelid elevator, you would not have a "triple" fold and a hollow sulcus.  The treatment is to repair the septal scar that develops in these eyelids.  Generally what is going on here is that fat was removed with the double fold surgery and a septal scar develops that disinserts the elevator aponeurosis off of the tarsus.  This also implies that your original surgeon did not perform an anchor blepharoplasty which is an essential surgical maneuver to make a permanent upper eyelid crease.  There is no substitute for a personal, detailed assessment, and going to surgeons who know what they are talking about.