The study examined why lower eyelids get bulgy with age by looking at the faces of people in three different age groups (12 - 29 years old, 30 - 54, and 55 - to 80) via magnetic resonance imaging (MRI).
In the research, plastic surgeons discovered that while the rest of the face loses volume with age; lower eyelids actually get fatter.
This significant increase in orbital fat is the primary cause of under-eye bags.
Previous studies have hypothesized that the "bags" were caused due to swelling from fluid build up or sagging/drooping of the eyelid/upper cheek area.
The latest study confirms that excision or removal of the fat, during eyelid surgery, not just repositioning, plays a clear role in the treatment of under eye bags. More than 240,000 eyelid surgeries were performed in 2007, according to ASPS statistics.