Would a blepharoplasty in my 20s cause future complications? Can asymmetrical eyelids be treated with a Botox brow lift? (photo)

As we age, our eyelids naturally sag and droop. A combination approach would be best to see visible improvement. In terms of non-surgical treatment options, I would recommend a Chemical Brow Lift (using Botox, Dysport, Xeomin, or Jeuveau) and filler injections to rejuvenate the temples, eyebrow, eyelid, eye troughs, upper eye hollows, and forehead. I typically combine this with Ultherapy and thread lifting to lift the brow; RF and skin tightening laser treatments to stimulate collagen production and rejuvenate the skin; and laser or superficial RF devices for improvements in texture, color, and any crepey skin around the eyes as needed. In some cases, surgery is the best solution to achieve the desired results. See an expert for a formal consultation. Best, Dr. Emer.​

Thank you for your question. I am glad to hear your upper eyelid function does not interfere with your visual fields. However, ptosis can range in severity from very mild to severe. Persons with mild ptosis do not have visual field obstruction, whereas those with moderate to severe ptosis do.
That said, you may very well be correct in your assessment that you do not have ptosis. Standard photos (frontal, oblique, and lateral) as well as a video demonstrating your upper eyelid excursion (how much your eyelids move) would be necessary to really look at your eyelid shape and function. Of course, a detailed in person exam would be better still.
If you do not have ptosis, than upper blepharoplasty may help you achieve the eyelid symmetry you desire. If you do have ptosis an upper bleph plus a ptosis repair is needed.
Regarding botox and brows, the answer is generally yes. Well executed botox injections can elevate then lateral brow and lift the eyelids. This is often an effective initial strategy if the person in question has mild upper eyelid asymmetry and/or does not want surgery.

Even though you have no vision problems, you do have ptosis. That is what is causing the asymmetry. See a plastic or ophthalmic plastic surgeon who is an expert in treating this. See the last example in the web reference.