Hollow under-eyes happen because the skin beneath your eyes is some of the thinnest on your body, with very little fat underneath it. When that already-minimal cushion of fat shrinks, shifts, or was never very thick to begin with, you see a sunken groove between your lower eyelid and cheekbone. This area is called the tear trough, and its depth depends on a mix of genetics, aging, and everyday habits.
The Anatomy Behind the Hollow
The under-eye area sits directly over the orbital bone, your eye socket. A thin layer of fat and connective tissue separates the skin from that bone, and a ligament anchors the skin down along the rim of the socket. When there’s enough fat volume, the transition from lower eyelid to cheek looks smooth. When that volume is low, the ligament creates a visible depression, almost like a valley running from the inner corner of your eye outward.
The shape of your cheekbone matters too. If your upper jawbone (maxilla) is more prominent, there can be a larger gap between the bone and the overlying skin, which makes the trough deeper. That same bone structure can pull the anchoring ligament tighter, carving out a more noticeable groove. This is why two people the same age can have very different under-eye contours.
Why It Gets Worse With Age
Aging affects the under-eye area from multiple directions at once. The fat pads that sit deep beneath your cheek gradually shrink in volume and slide downward. As that deep fat deflates, the superficial fat above it loses its support and droops too. The result is a flattening and hollowing of the entire zone from the lower eyelid down to the cheekbone.
The bone itself also changes. CT imaging has shown that the facial skeleton undergoes a slow rotation and resorption over time, particularly in the area just below the eye socket and along the cheekbone. Less bone means less scaffolding for the soft tissue above it, which deepens the hollow further. These skeletal changes tend to become noticeable in your 40s and 50s, but the fat volume loss often starts a full decade earlier.
Genetics and Early-Onset Hollows
Not everyone who has hollow under-eyes is aging into them. Some people inherit the look. If your parents have deep tear troughs, you likely have a naturally thinner fat layer in that area or a bone structure that creates a steeper drop-off between the eye socket and the cheek. People with naturally thin skin around the eyes are especially prone, because there’s less tissue to mask the contour of the bone beneath.
Inherited hollows can show up as early as your teens or twenties and tend to stay relatively stable until age-related volume loss accelerates them.
Lifestyle Factors That Make It Worse
Several everyday habits can deepen the appearance of under-eye hollows, even if they aren’t the root cause.
Dehydration. When you’re not drinking enough water, the soft tissue beneath your eyes loses water content and shrinks slightly. Because the skin there is already paper-thin, even a small reduction in tissue volume makes the area look more sunken. Your skin can also lose some elasticity when you’re chronically dehydrated, which compounds the effect.
Poor sleep. Chronic sleep deprivation thins the skin, shifts fluid distribution under the eyes, and makes the skin less opaque. All three of these changes let the underlying hollow show through more prominently. A single rough night won’t permanently change your anatomy, but weeks or months of poor sleep can make a mild hollow look significantly deeper.
Significant weight loss. Losing a large amount of body fat doesn’t just slim your waist. It reduces the fat beneath your eyes too, and that fat doesn’t come back easily even if you regain weight elsewhere.
Allergies and Sinus Congestion
If your hollows seem to come and go, or look worse during allergy season, your sinuses may be involved. Nasal congestion slows blood flow in the veins that run just beneath the under-eye skin. When those veins swell, the area looks darker and puffier. Over time, repeated cycles of swelling and deflation can stretch the skin and make the underlying hollow more visible even when allergies aren’t flaring. This pattern is sometimes called “allergic shiners,” and treating the underlying allergy often improves the appearance noticeably.
Nutritional Deficiencies to Consider
Iron deficiency anemia reduces the amount of oxygen your blood carries, and one visible sign is darkening of the under-eye area. The combination of dark discoloration and naturally thin skin can mimic or exaggerate the look of deep hollows. If your under-eye changes came on alongside fatigue, pale skin, or shortness of breath, a simple blood test can rule this out. Correcting an iron deficiency won’t fill in a structural hollow, but it can eliminate the shadowing that makes it look worse than it is.
How Severity Is Assessed
Doctors use a straightforward grading scale when evaluating tear trough depth. Grade 0 means a smooth, youthful contour with no visible line at the eyelid-cheek junction. Grade I is a mild, subtle shadow mostly on the inner side. Grade II shows a moderate groove extending from the inner corner outward. Grade III is a severe, obvious step-off between the eye socket and the cheek. Knowing where you fall on this scale helps determine which treatments, if any, are appropriate.
What You Can Do at Home
Home measures won’t eliminate a structural hollow, but they can reduce how pronounced it looks. Staying well-hydrated keeps the tissue beneath your eyes as plump as it can be. Prioritizing consistent sleep (seven to nine hours) prevents the skin thinning and fluid shifts that worsen the appearance.
Retinol-based eye creams can help over time by stimulating the skin to produce more collagen, gradually thickening the under-eye skin so the hollow beneath it is less visible. Results are subtle and take weeks to months, but retinol is one of the few topical ingredients with a real mechanism for improving this area. Start with a low concentration and apply it sparingly, since the skin here is sensitive.
Filler Treatments
Hyaluronic acid filler injected into the tear trough is the most common non-surgical option for under-eye hollows. The filler adds volume directly where it’s missing, smoothing the transition between the lower eyelid and cheek. Results are typically visible immediately and last longer than many people expect. Research published in the Journal of Clinical and Aesthetic Dermatology found that improvements persisted well beyond the commonly cited 6 to 12 months, with significant results still evident at 18 months and clinical observations suggesting benefits lasting up to 24 months.
The trade-offs are worth understanding. Common side effects include bruising, swelling, and occasionally a bluish-gray tint under the skin (called the Tyndall effect) if filler is placed too superficially. Delayed complications, though less common, include persistent swelling, small lumps, and filler migration. These delayed issues appeared on average around 17 months after treatment in one review, so follow-up appointments matter even when everything looks good initially.
Surgical Options
For more severe hollowing, or when fillers aren’t producing the desired result, surgical approaches offer longer-lasting correction. The two main techniques are fat repositioning and fat grafting.
Fat repositioning is done during lower eyelid surgery. Instead of removing the puffy fat that bulges outward (which can actually worsen hollowing), the surgeon moves it downward into the hollow. This preserves the eye’s natural fullness and creates a smoother contour that ages well over time. Fat grafting takes a different approach: fat is harvested from another part of your body, purified, and injected into the tear trough area. This adds soft, natural-feeling volume and may improve skin quality over time due to growth factors naturally present in fat tissue.
Recovery for both procedures runs about 7 to 10 days, with swelling and mild bruising that fades quickly. Most people are back to normal routines within two weeks, using makeup to cover any lingering discoloration. Final results develop gradually over several months as the tissue settles into its new position.