Uneven Swelling After Upper Blepharoplasty

I had upper blepharoplasty done 3 weeks ago and the swelling in my right eye has gone down considerably, but my left eye is just as swollen as it was when I got my stitches taken out 5 days after surgery. I've been iceing the left eye a lot more than the right eye to reduce the swelling but it doesn't seem to be helping at all. Why is my left eye still so swollen while my right eye is fine, and what can I do to make it un-swell? Is this going to last for months?