Lower blepharoplasty surgery sometimes involves removing "excess" orbital fat. As we get older, the orbital fat stays the same (it may bulge out a little more) but the cheek fat descends lower onto the face. The hollowness between these two areas is the tear trough. Adding fat or filler into this area fills in this groove and restores a more youthful appearance.There are advantages and disadvantages to using fat vs. fillers. One of the more common shelf-available fillers is hyaluronic acid (HA). This can be placed under your eye to fill in the area that appears hollow. It is not permanent, so additional treatments would be needed if you like the result that you get. If you don't like the result, hyaluronidase can be injected to help dissolve the product expeditiously.Free fat transfer can be a permanent improvement. Percent fat survival after a treatment varies (30-100%). You also have to have the fat harvested from a donor site. If you gain weight later, the transferred fat under the eye can also increase in volume.I would probably start off with a vial of HA filler and see if you like it. If so, free fat transfer is always an option. If you don't like it, you can either wait for it to dissipate over the course of 6-12 months or have your surgeon inject some hyaluronidase.