Concerns about what you see
16 y/o's usually do not have such concerns and I would want to know the background behind where you came to this conclusion. As a minor, no ethical surgeon would attempt anything at this time. As an adult, you can see surgeons about your concerns and if problems are present, pursue procedures to help you achieve your goals.
I would agree with Dr. Seckel.
The only exceptions I make for teenagers are trauma, tumors, congenital issues, and cosmetic concerns in working models and actresses who are currently making a living with the face. You will probably benefit from a very refined upper blepharoplasty at some point. On the other hand, if this is not done well, you can be crippled emotionally by a bad result. For this reason, it is reasonable to allow the face to fully develop before having eyelid surgery.
Excess skin under eyebrows an 16-year-old
Based on your photograph the excess skin covering the fold above your eyelashes appears to be excess eyelid skin. Next
In my opinion 16 years old is too young to have surgical correction of this problem.
After your facial growth is complete, certainly after 18 years of age if you continue to see loose fold of skin on your upper eyelids then consult a plastic surgeon for the possibility of an upper blepharoplasty.