One Eye Bigger Than the Other? (photo)

You do have marked facial asymmetry.  The left eye does appear much smaller than the right.  This is not simply a cosmetic issue.  You need to be assessed for this.  Is this a new phenomena that is getting progressively worse.  This might be consistent with a syndrome called the "silent sinus syndrome."  This is caused by closure of the maxillary sinus due to sinus disease which results in the sinus collapsing.  The cure is to open the sinus with sinus surgery and repair the orbit if indicated.  Other causes may not be progressive such and having eyes of different size.  Sometimes the issue is heaviness of the eyelid that makes one eye appear smaller.  Expert assessment will determine the basis for this asymmetry and what should be done if anything.  This is not just a cosmetic issue.  The American Society for Ophthalmic Plastic and Reconstructive Surgery maintains as website with a regional directory that can help you find a well qualified surgeon in your area to consult with.

Good question. If you look closely, almost everyone has some degree of facial asymmetry. In fact, people with complete facial symmetry often have a slightly visually "odd" appearance to our brains. You are certainly correct, your right eye appears slightly larger than the left, but overall it is quite difficult to tell unless looking closely. I would make sure that this is not something that has progressed or changed over time as it can be a marker of underlying eye issues (ptosis), though I think this is less likely. If this is mostly bothersome in photos, then there are certainly ways to address this (ie closing both eyelids slightly to compensate). As far as non-surgical options, I would be hesitant to suggest that anything will make a noticeable difference as this is such a subtle difference to start with.
Hope this helps!Kyle Kimura, MDFacial Plastic and Reconstructive Surgery

It's difficult to say without the benefit of a formal evaluation. This is my expertise and a huge portion of my practice. Asymmetry is normal and expected. See an expert who does facial shaping with surgical and non surgical methods to get a comprehensive option. Best, Dr. Emer.