Sunken under-eyes happen when the fat pads beneath your lower eyelids thin out, shift downward, or were never very prominent to begin with. The result is a hollow groove, sometimes called a tear trough, that runs from the inner corner of your eye toward your cheekbone. This can make you look tired or older than you feel, and it has several overlapping causes ranging from normal aging to genetics to lifestyle habits.
The Anatomy Behind the Hollow
Your lower eyelid area isn’t just skin and muscle. Underneath sits a layer of fat divided into three distinct pads (medial, central, and lateral) that cushion your eye and keep the under-eye area looking smooth and full. These fat pads are held in place by a network of ligaments that anchor tissue to the bone beneath.
The most important of these is the tear trough ligament, which runs from the inner corner of your eye along the rim of your eye socket. When this ligament weakens or the fat pads behind it shrink, the groove it creates becomes visible through the skin. A second structure, the orbicularis retaining ligament, is weakest in its central portion and stretches more easily over time, allowing the middle fat pad to bulge forward while the area below it sinks inward. That combination of puffiness above and hollowness below is what gives many people the classic “tired eyes” look.
Why Aging Is the Biggest Factor
Three things happen simultaneously in your face as you get older, and all three deepen under-eye hollows.
First, the fat pads beneath your eyes shrink. This process, called fat atrophy, removes the volume that once kept the area looking full. Second, the ligaments holding everything in place loosen, so whatever fat remains slides downward and forward. Your eyeball itself actually descends slightly within the socket over time, pushing infraorbital fat anteriorly and making the trough more prominent.
Third, and less obviously, the bones of your face are slowly resorbing. The eye socket enlarges by roughly 2.3 mm in height and 1.8 mm in width per decade. By your 70s, the orbit may be 15 to 20 percent larger than it was in your 20s. That means the bony shelf supporting your under-eye area is literally receding, giving the soft tissue above it less structural support. The periorbital region is especially vulnerable to this kind of bone loss because it experiences less mechanical stress than areas like your jaw.
Genetics Play a Real Role
Some people notice sunken under-eyes in their 20s or even their teens. If your parents had deep-set eyes or prominent tear troughs, you likely inherited a bone structure with less projection at the infraorbital rim or naturally thinner fat pads in that area. The vascular component of dark circles, which often accompanies hollowing, follows a dominant inheritance pattern, meaning only one parent needs to carry the trait for you to show it. So if hollows run in your family, aging isn’t the only explanation.
Dehydration, Allergies, and Sleep
Lifestyle factors won’t create a true structural hollow, but they can make an existing one look dramatically worse. Dehydration thins the skin and reduces its turgor, making underlying anatomy more visible. Even mild fluid loss can deepen the shadow under your eyes noticeably within a day.
Allergies are another common culprit. When your immune system reacts to an allergen, the moist lining inside your nose swells and slows blood flow through the veins around your sinuses. These veins sit very close to the surface of the skin under your eyes, so when they become congested, the area looks darker, puffier, and more hollowed out by contrast. This is what doctors call “allergic shiners,” and the discoloration can persist for as long as the congestion does.
Chronic sleep deprivation, smoking, excess alcohol, and unprotected sun exposure all accelerate collagen breakdown in the thin periorbital skin, compounding the appearance of hollowing over time.
What Topical Products Can (and Can’t) Do
Eye creams won’t rebuild lost fat or reverse bone resorption, so expectations matter here. That said, certain ingredients offer modest, real improvements to the skin itself.
Retinoids (prescription tretinoin or over-the-counter retinol) increase collagen density in the deeper layers of skin, making it thicker and more resilient over months of use. Thicker skin means the underlying hollow is less visible, and the texture looks smoother. This is a long game: you won’t see results for 8 to 12 weeks at minimum.
Caffeine-based eye creams work through a different mechanism. Caffeine constricts small blood vessels and reduces fluid retention, which helps with puffiness and the dark, congested look that often accompanies hollows. In one review, 75 percent of patients showed improvement in puffiness with caffeine-containing formulations. It won’t fill a hollow, but it can soften the overall appearance.
Dermal Fillers for the Tear Trough
Hyaluronic acid filler is the most common non-surgical option for sunken under-eyes. A practitioner injects a small amount of gel, typically around 0.45 mL per side, directly into the tear trough to restore the volume that fat loss or bone changes have taken away. The procedure takes about 15 to 30 minutes with minimal downtime.
Results were once quoted as lasting 6 to 12 months, but more recent data suggests they persist significantly longer. A retrospective study published in the Journal of Clinical and Aesthetic Dermatology found that tear trough fillers maintained meaningful results up to 18 months after treatment. The under-eye area is relatively low-movement compared to the lips or cheeks, which may explain the extended longevity.
Filler isn’t right for everyone. If the hollow is caused primarily by excess skin laxity rather than volume loss, adding filler can create a lumpy or overfilled look. A skilled injector will assess whether your hollowing comes from volume loss, skin quality, or both before recommending treatment.
Surgical Options for Deeper Hollows
When fat pads have both atrophied and shifted significantly, surgery may offer a more lasting correction than filler. The most common approach is a transconjunctival lower blepharoplasty, where the surgeon accesses the fat pads through an incision inside the lower eyelid, leaving no visible scar. Rather than simply removing the bulging fat (which can worsen hollowing over time), many surgeons now reposition it, draping the displaced fat downward into the tear trough to fill the hollow naturally.
This fat repositioning technique has shown superior long-term maintenance of results compared to combining fat removal with separate fat grafting. Recovery typically involves a week or two of swelling and bruising, with most people returning to normal activities within 10 to 14 days.
Practical Steps That Help
If your sunken under-eyes are mild or mostly driven by lifestyle factors, a few changes can make a visible difference. Staying well-hydrated keeps skin plumper and reduces the shadowing effect. Treating nasal allergies with an antihistamine or nasal spray can resolve the venous congestion that darkens and deepens the area. Sleeping with your head slightly elevated helps prevent overnight fluid pooling that accentuates hollows in the morning.
For sun protection, a mineral sunscreen or physical barrier like sunglasses slows collagen degradation in the periorbital skin, which is thinner and more vulnerable to UV damage than almost anywhere else on your body. Combining daily sun protection with a retinoid at night gives you the best topical strategy for preserving skin thickness over time.