Anatomic deformity that is very minor as compared to others. Try Fillers and BOTOX as great noun invasive options...
If, as you say, your photo is a straight shot and there is no tilt of your head, then it looks like you have orbital dystopia. Your facial skeleton has grown such that one eye socket is now at a different height to the other. You state that it was not always like this. You don't mention your age, but do you remember when you first noticed this difference? There may be an underlying condition that needs investigation and treatment. You should consult with a craniofacial surgeon and you should have some scans done of your facial skeleton.
Uneven eyes/eyebrows is very common and almost everyone has it. Yours is minimal and you should leave them alone. You can always find a surgeon to operate and u will be unhappy.
Actually asymmetry is the rule rather that the exception as we all have one dominant eye which will be a bit larger. The asymmetry can be reflected in the brow as well. Not always like that? Perhaps growth and facial maturity are showing.
The funny thing is that you might also have right upper eyelid ptosis. You need a careful assessment of the eyelids by a very experienced oculoplastic surgeon who focuses on cosmetic eyelid surgery. It is critical to determine if you need ptosis surgery for just the left eye or both eyes. Correcting only one side when both need to be done will lead to a situation where the currently normal looking eye appears heavy after surgery. For you it is also essential to maintain you low upper eyelid fold. Then the eyelids are lifted, there will be slightly too much skin. For this reason, a small anchor blepharoplasty with the surgery is likely to also be necessary to obtain an optimal result.