Your left brow is a little lower so that the skin sits lower on the lid. This makes the eye appear smaller. No evidence ptosis in these photos. Try some botox to elevate the left brow and see if that helps.
Some asymmetry may be normal. I would recommend seeing an oculoplastic surgeon to examine you so that you may have your question answered accurately. Best wishes.
One eye bigger than the other?
There are numerous reasons for eye asymmetry including eyelid asymmetry and eyeball position asymmetry. See video below. See an oculoplastic specialist.
You have mild upper eyelid ptosis.
There is significant right eyebrow compensation. This suggests that the effect of the ptosis on the right side is more significant even if in this photograph the amount of ptosis appears to be about the same amount. A very careful consultation would determine which of the ptosis surgeries is best for you. However given the compensatory brow elevation, a microblepharoplasty approach can be used to repair the disinsertion of the right levator aponeurosis. This can be done to effectively lower the right upper eyelid crease height to match the left side.
The positions of your actual eyelids appear symmetric. Look at their position relative to the borders of the pupil & iris. One eyebrow may be a bit higher than the other thus "uncovering" one upper eyelid more than another. This may be "real" or this may be that you reflexively tend to hold one higher than the other. Well done Botox/Dysport/Xeomin may provide satisfactory improvement.