I Am 20 and Have Enormous Puffy Bags Under my Eyes. What Kind of Surgery Should I Get?

It is not unusual to see this type of "puffiness" at your age. The most effective way to resolve your problem is to have a transconjunctival lower blepharoplasty. It is critical that your surgeon be very conservative with fat removal because you could appear hollowed out if too much is taken. It is better to surgically under-treat than over-treat your problem. I hope you find this helpful.

Bags under the lower eyelids are usually caused by displaced fat, redundant muscle, redundant skin, or sometimes even a prominent vascular plexus giving the aesthetics of lower lid bags or dark circles.
Early volume loss in your upper cheek and tear trough area can exacerbate even a small amount of genetic predisposition to having eye bags. There are numerous, good options to address this issue ranging from nonsurgical to surgical.
It is important to realize that it is displacement of fat, NOT excess fat that can cause lower lid bags. Old school blepharoplasty approach took skin and fat out of the lower lids by cutting right through the skin, which gave long term poor results with hollowed out lower lids and more potential for surgical complications. 
We know that we tend to lose fat as we age in our face, so taking more out as part of a surgical procedure may look good immediately, but it is a long term bad idea. Newer approaches to lower lid blepharoplasty do not cut through the skin and leave no external scars, this is called the transconjunctival approach. More important yet, the existing fat is repositioned instead of removed, giving much better long term results with a more conservative surgical technique that also has lower potential for complications. 
Nonsurgical options include strategically placed volume to replace early loss, which can have a dramatic impact on the appearance of eye bags and the junction between your eyelids and cheek. Volume can come in the form of fillers or as micro fat grafting. 
To ensure you are receiving the highest level of care, seek out a modernly trained, new-school dermatologic surgeon, oculoplastic surgeon, facial plastic surgeon or plastic surgeon who is board certified and fellowship trained in one of these “core four” cosmetic specialties. Membership in organizations like the American Academy of Facial Plastic and Reconstructive Surgery help to identify a highly trained surgeon.
Cameron Chesnut
#realself500 Physician

First, I would recommend treating your allergies to understand how bad the puffy lids truly are.  If the puffiness remains after allergy treatment, at your age, you can easily have a transconjunctival blepharoplasty which uses a small incision behind the eyelid (so no scar on the skin) and removes the fat.  The procedure takes about 45 min to perform.

Thank you for your question about eye bags treatment.  Fillers are often an excellent choice for the treatment of this area, but filler only camouflage the appearance of these bags...and eventually surgical intervention may be necessary.  It is vital that you are seeing a seasoned professional for this area of the face.  If the filler is placed incorrectly it can make the prominent eye bags even worse.  The use of a cannula in this area can minimize bruising and the risk for vascular compromise.  
To be sure, see two or more experienced, licensed and board-certified providers in your area for a complete evaluation to make sure you are a good candidate and that it is safe for you to have treatment. I hope this helps. 

I would first start with some filler to the lower lids, namely restylane.  If this does not improve the appearance, a lower lid blepharoplasty with fat repo with a transconjunctival incision is the way I would good.  Obviously an in person consultation is needed to make any surgical decision.
Dr Z

There are many causes of eye bags. Some are shadow issues, some are discoloration issues.  Most people have a multifactorial problem meaning they have more than one issue causing this demarcation. Below is a list of common issues and my treatment protocols. 
1. Prolapsed orbital fat through the orbital septum: treated with lower lid blepharoplasty and fat transpositioning. Can also be helped with fillers or auto fat transfer to the face but the ideal treatment in my hands is surgery for this issue.
2. Eczema: much more common in young people with fair skin. The treatment for this is to hold off on makeup and any manipulation of the lower lid for a few weeks and try some topical anti inflammatory creams. If you have allergies those should be treated also.  A dermatologist is the best person to see for this. We have a multidisciplinary clinic with myself, a plastic surgeon, and my partner, a dermatologist which I think is ideal!
3. Fluid accumulation and/or redundant skin. Could be possible in young patients but would need a good facial analysis and exam to determine. A low salt diet (< 1000mg/day) and a warm compress can help.  I would consider treating with filler/fat transfer, lower lid fractional ablative laser and/or lower lid blepharoplasty.
4. Descent of midface cheek pad. This then causes the nasojugular ligament to become more prominent creating a demarcation and separation of the eye from the cheek subunit. Treated with mid face lift and/or fat transfer.
It is all about the balance of this transition from the orbit to the cheek. There are many ways to treat this and they vary by the underlying cause. I recommend seeing a surgeon who also does a lot of these treatments. This can make a big difference as most people have a combination of the above that lead to the issue.
Hope this helps.
Best of luck,
DrC