Eyelid Surgery to Make Eyes Look Even?

There may be many explanations for this ranging from skeletal to muscular to fatty to cutaneous causes. Depending on the findings a variety of interventions could provide you with dramatic improvement.
However, It is not realistic to expect perfect symmetry.
Seek a qualified surgeon and discuss what can and cannot be corrected. IT is common to overcorrect in anticipation of settling and relaxation of tissues.

Dear Maplesyrup
There are a number of reasons that the two eyes can look different including that this is the way you come. You have not included a photograph so it is hard to be more specific.
Before considering how to make the two eye look the same, it is important to determine why they look different.
The very first thing that I would be concerned with is if you have a thyroid imbalance that might account for why one eye opens more than the other. This might be do to upper eyelid retraction or so-called proptosis or bulging of the eye. Thyroid eye disease is pretty common and sometimes develops in individual with normal thyroid function but more commonly it is seen in individuals with an over active thyroid. Most of the eye changes are seen within a couple of years of when the thyroid becomes overactive. Blood work by your primary care physician can assess the function of the thyroid and an examination by an ophthalmologist would help determine why you have this asymmetry.
There are of course numerous possibilities. A work up by an ophthalmologist or an eye plastic surgery is indicates. Once a diagnosis is established a treatment plan can be developed to address your appearance. It is important not to get the cart before the horse. Start by seeing someone to determine why you have the asymmetry and then see where that takes you.

 Dear Maple Suryp
Make the eyes look more symmetrical can be tricky. The contour/shape of the eyeball is fixed.  the soft tissues of the orbit can be shaped along with lower eyelid postion can be maniputlated to make the eyes look more similar.
With Warm Regards,
Trevor M Born MD