See an oculoplastic surgeon for evaluation. You have upper eyelid ptosis, so you may be candidate for eyelid ptosis surgery, to make the eyes bigger.
though there are several operations that could give you slightly bigger eyes, the complications associated with those outweigh the advantages that would be gained with your particular eyes. Remember that all surgery comes with risks and I would suggest you do nothing.
To a certain extent you can make the eyes more open. Making them bigger horizontally is more challenging. Looking at your picture it appears you could have your eyes opened more vertically (ptosis surgery). This could also improve the symmetry between the two sides. To give more of a "cat-eye" look you can have your outer corners raised just a bit (canthopexy). The ptosis surgery to make your eyes more open vertically can be done internally if a phenylephrine test works well or externally (through the skin) if it doesn't work well. Your concern would require a very experienced eyelid surgeon. Fellows of the American Society of Ophthalmic Plastic Reconstructive Surgery (ASOPRS) are very well trained in eyelid plastic surgery, and generally perform the most surgeries that you are requesting. Best regards.