Hi Vivid252850, thank you for your question and photo. When one eye appears bigger, it is almost never the eyeball itself. From your description and photo, the usual causes are a slightly lower upper lid on one side (ptosis, a weakness of the lid-lifting muscle), extra skin folding over one lid, or a difference in brow height pushing one lid down. Each of those has a different operation, and choosing the wrong one makes things worse rather than better. It is also worth saying that every face has some asymmetry, and lids that differ by a millimetre are within normal. The key measurement is where each lid margin sits relative to the pupil, which takes minutes to assess in person. I would see an oculoplastic-trained surgeon for an in-person examination before deciding on any surgery, and I would be cautious of anyone offering an operation without first naming the precise cause.