Fullness of the upper eyelids come from two places.
• One is the position of the eyebrows. If the eyebrows are low, in position, this adds fullness to the upper eyelids.
• The other factor is true excess upper eyelid fat and skin which honestly, is a bit rare at 31 years old. Now
In women, the proper aesthetic shape of the eyebrows and eyes must be determined in person by the plastic and cosmetic surgeon in order to determine which of the abovementioned two factors is causing the upper eyelid fullness in your particular case. I mention this in my new book on the aesthetics of beauty , "What's Your Number..the palmer code." the link to which is included at the bottom of this answer.
The surgeon must, IMO, place your eyebrows in the proper aesthetic position and then with you opening and closing your eyes, assess the amount of upper eyelid fullness remaining. There are three possible outcomes all quite revealing:
• when the eyebrows are elevated to the proper position, all the upper eyelid fullness is gone. This means the fullness is due to low eyebrows and the solution is a Brow Lift, not an upper Blepharoplasty which if performed, in this scenario, would actually cause your eyebrows to become lower after the procedure. More on this later.
• when the eyebrows are elevated, some of the upper eyelid fullness remains. This indicates that a Browlift would remove some, but not all of the fullness, the remainer of which could be removed with an upper Blepharoplasty as a combined procedure.
• the eyebrow is already in the proper position and all of the fullness remains, indicating that an upper Blepharoplasty alone would remove this excess. This is the only scenario, of the three possible, where an upper Blepharoplasty alone is indicated.
Until this simple, but crucial maneuver is performed on you in person...I don't see how an accurate answer can be provided. If an upper Blepharoplasty is done when the correct procedure should have been a Brow Lift, to raise the eyebrows, the Blepharoplasty can cause the position of the eyebrows to go even lower after the procedure. Once this happens, the Brow Lift often can't be performed because there's simply not enough skin on the upper eyelid to allow the eyes to close properly after the eyebrows have been elevated. This can result in corneal exposure and complications.