How to Improve Uneven Face?

On a temporary basis, Botox can usually even out many asymmetries.
On a more permanent basis, asymmetric browlifts as Dr. Rand suggests are a good option.

 Though no face is perfectly symmetrical your correct in your analysis of your problem. A unilateral browlift will give you much better symmetry. This is a 30 minute procedure and there is very little bruising. I let foreign patients go back home in 2 days.

It is completely normal to be slightly asymmetrical, and everyone has some degree of asymmetry! The good news is that we rarely notice it with other people. If the asymmetry really bothers you, then you could consider using Botox injections to help lift the lower eyebrow. I don’t think your asymmetry warrants surgery. Risk and reward must be weighed, and I would be more concerned with a scar (no matter how elegant) that would result from a brow lift. I recommend consulting with a board-certified plastic surgeon to discuss your concerns and goals.

for mild assymetry you can do botox for browlift,but on only on the side of assymetry.but it needs to be done every 4-6 months

Every face has asymmetry due to embryologic development of facial features. The degree of asymmetry is variable depending upon each person. The mirror image of the left side of the face does not equal the mirror image of the right side. When the brows are asymmetrical whereby one eyebrow is lower than the other these can be adjusted through a browlift. Asymmetrical eyelid surgery can also be performed. By removing more skin and/or excess fat on one eyelid versus the other this would allow both eyelids and eyebrows to be more symmetrical.

Asymmetry is a RULE of nature. No face (or a pair breasts) is symmetrical. For example, your right eye is different from the left. Your Left upper lip is different from the right. The moles on your right lower lid and right jaw line are not matched on the left.
As much as it may "bug" you - you should always weigh potential benefits against the real potential to make things worse. Botox, used expertly (see link below) can be used to gently lower the right brow. Only a small dose is needed just above the surprised look maximal arch elevation. Excessive dropping of this arch can result in brow flattening, excess upper lid skin and increasing eye asymmetry.
I would NOT use Botox if you are breast feeding though. (You posted a question elsewhere "Should I wait until after breast feeding to have Breast Implants?")
Dr. P. Aldea

 While everybody has facial asymmetry to some degree, what you are pointing out is quite visible.  A unilateral browlift would be what I would suggest.