Options for Correcting Asymmetry After Lower Blepharoplasty?

The lower eyelid that is "higher" has had less skin retraction that the one that is "lower and rounder" more skin retraction. This can be improved with non surgical approaches and if considerable possibly a minor revision. It is unlikely that skin was removed only from one eyelid and not the other. Talk to your doc about your options.

The best thing to do is to discuss your situation while looking at the preop photos together with your surgeon. Anytime an incision is made on the lower eyelid for blepharoplasty, there is a chance that scarring will pull the lid down, even if the procedure was performed correctly. Early in the postoperative period, this can often be corrected with massage. However, since you are 4 1/2 months out from surgery, it will probably not help. Small changes can usually be corrected with a small surgery called a canthoplasty if needed. Be sure to go over your pictures with your surgeon. Good luck.

Dear Sueesquisite
This is highly precious real estate that you are describing. The challange in improving these types of asymmetries is that the analysis of the problem is often beyond the scope of the surgeon's ability to understand what you are describing. Their brains may glaze over when you are descrbing your concerns unless by training and by practice, they are comfortable dealing with these types of issues ( a very rare thing). The ethical surgeon may simply tell you that there is nothing that can be done, or that you look great and you are dwelling on very minor issues that no one else will notice.
The key is finding a doctor who will carefully and nonjudgementally listen to your concerns, examine you and then detail precisely what the issues are is sufficient detail that it is clear they understand what you are talking about and then have a precise plan to address these issues.

Achieving perfect eyelid symmetry with eyelid surgery is impossible. This is because the two eyes are not symmetrical prior to surgery, and despite perfoming a good blepharoplasty, the tissues on both sides can heal differently.
It is very common to initially see significant differences between the two eyes, but this should get better after 4-6 months. Obviously, there is always a possibility that surgery itself can cause ectropion or other abnormalities, but you need to give your eyes time to heal before judging the results and thinking about possible revision surgery.

The eyelids themselves are naturally asymmetrical on nearly every patient. Unfortunately, your asymmetry is probably accentuated from the surgery that you had. Festoons are almost impossible to get rid of since they are not part of the eyelid complex and are located more on the malar cheek pad area. Options are available to attempt to make the eyelids more symmetrical and include different placement of incisions, removal of asymmetrical fat and/or canthoplasty. Check with a reputable surgeon who has lots of experience in this area.