Just fixing the left eye will suddenly make the right upper eyelid heavy. That is because you are putting energy into both eyelids to open the eyes. In fact the right brow looks higher than the left brow. After surgery on just the left eye, the incentive to hold the eyes open will be reduced and suddenly it will make the right upper eyelid look heavy. For this reason both upper eyelids need to be carefully assessed. I would be very conservative with the upper blepharoplasty. Less is more. The American Society for Ophthalmic Plastic and Reconstructive Surgery maintains a regional directory that can assist you to find a highly qualified oculoplastic surgeon (ASOPRS dot org).
You certainly do have subtle ptosis on both eyelids and a conservative ptosis and blepharoplasty could be considered. Based on your photos, I don't believe that it is affecting your vision, so this will likely be a cosmetic surgery that your insurance will not cover. However, an in person consultation would be required to determine that.
I have posted a photo of a similar patient. This patient had ptosis surgery only, without any blepharoplasty.
It is best to obtain in person consultation, examination. There appears to be mild eyelid ptosis left more than right, but not sure if enough for surgery yet. See an oculoplastic surgeon.