What possible causes for my face sagging and hollow eyes (23 years old) (photos)

Hi @jazzy343. Thank you for sharing your photos. I recommend a combination treatment of dermal fillers and Morpheus 8. Morpheus 8 is a non-surgical treatment for full body skin resurfacing, skin tightening, and fat reduction of stubborn areas. It uses minimally invasive fractional radiofrequency energy (RF) to penetrate the skin deeper than other microneedling devices, triggering the skin’s natural healing response to promote skin tightening and lifting.

Best of luck,

Dr. Nima

I would suggest that you not seek surgery without a thorough evaluation by an internist. I have not seen this type of facial atrophy and sagging in anyone at your age. We need to rollout causes 

First and foremost, it's important to check with your primary care physician to rule out serious medical conditions or problems.Loss of volume is a typical sign of aging, and the truth is that these signs can begin to show up much earlier in some people than others. Lips, cheeks, and temples are often the first to lose "fullness." However there are a number of options to restore volume. Juvederm and Juvederm Voluma can provide a healthy, youthful, "plump" (in the best sense) to skin for one or two years respectively. A more long term solution, though more invasive, is a fat transfer procedure. Make sure you research your options and get a personalized recommendation (or two) as to which is the best option for you. 

First you need a complete medical evaluation. This includes a detailed assessment of your diet, weight history, exercise history and when you first noticed this appearance that is concerning you now. Then a complete physical examination and evaluation for metabolic disorders, genetic conditions and systemic illnesses. If there is no problems with any of these areas there are definitely options to improve the appearance. These include procedures using either synthetic fillers or fat transfer to restore volume in hollow areas. There also surgical procedures and nonsurgical technologies that can be used to tighten loose skin. Since your present sagging appears quite minimal a nonsurgical treatment such as ThermiRF will probable acheive the tightening you would need. Best wishes

The facial tissues  are supported by the underlying bone structure/anatomy. In your case, the upper jaw (which extends up to the lower eye rim) is underdeveloped; and the lower jaw is very narrow (this makes the cheeks' look like jowls.) You would need a Maxillofacial surgeon to assess your structure and consider either moving the facial bones to provide more fullness support; or use augmentation materials to 'create' the image of the same thing.