Understanding Under-Eye Hollowness
Under-eye hollowness — clinically referred to as tear trough deformity — is one of the most common facial ageing concerns among adults in Ireland. It describes the depression or groove that forms beneath the eye, running from the inner corner of the eye downward and outward across the cheek. When this area loses volume, it creates a shadow that makes the eyes look sunken, tired, and older, regardless of how well-rested the person actually is.
The tear trough area is anatomically unique. The skin here is the thinnest anywhere on the body — typically just 0.5mm thick, compared to roughly 2mm on the rest of the face. It sits directly over the orbital bone, with minimal subcutaneous fat for cushioning and support. The orbicularis oculi muscle (the circular muscle that controls blinking and squinting) lies just beneath this delicate skin, and beneath that are the orbital fat pads that provide volume and smooth contour to the under-eye area in youth.
As we age, this finely balanced architecture changes. The orbital fat pads shrink and descend, the bone itself resorbs (loses mass), collagen and elastin in the thin skin decline, and the ligaments that anchor the tissue to the bone become more prominent as surrounding tissue thins. The result is a visible groove or hollowing that can extend from the inner eye corner to the mid-cheek.
What makes under-eye hollowness particularly frustrating is that it often creates an appearance of fatigue, illness, or age that does not reflect how the person actually feels. Many people in Ireland report that they constantly hear "you look tired" or "are you feeling okay?" — even when they are perfectly well and well-rested. This social feedback can significantly impact self-confidence and is a common motivator for seeking treatment.
It is important to distinguish under-eye hollowness from dark circles, though the two frequently coexist. Dark circles can result from pigmentation, visible blood vessels through thin skin, or shadows cast by hollowing — or a combination of all three. Addressing the hollow component often improves the appearance of dark circles by eliminating the shadow, but pigmentation-related darkness may need additional or alternative treatment.
What Causes Under-Eye Hollowness?
Under-eye hollowness develops through a combination of structural changes that affect the volume, support, and covering tissue of the periorbital region.
Age-related fat pad changes are the most significant contributor. The under-eye area contains several distinct fat compartments. In youth, these fat pads are full and well-positioned, creating a smooth, convex contour from the lower eyelid to the cheek. With ageing, these fat pads undergo two key changes: they deflate (lose volume) and they descend (shift downward due to gravity and weakening ligaments). The net effect is a depression in the tear trough, often accompanied by a bulge lower down (a malar mound or festoon) where the descended fat collects.
Bone resorption compounds the fat pad changes. The orbital bone — the bony rim surrounding the eye — gradually loses mass with age, a process that accelerates significantly from the forties onwards. This means the "shelf" that supports the under-eye tissues becomes smaller and less prominent, allowing the soft tissue to sink further into the orbit. This structural change is one reason why under-eye hollowing tends to deepen progressively with each decade.
Collagen and elastin decline in the under-eye skin makes the hollowing more visible. As the skin thins further and loses elasticity, it conforms more tightly to the underlying anatomy, revealing every contour and shadow. The loss of skin density also makes underlying blood vessels more visible, contributing to the bluish-purple discolouration commonly associated with under-eye hollows.
Genetics are a powerful determinant of under-eye hollowness. Some people have a naturally deeper orbital structure, less periorbital fat, or thinner skin — all of which predispose to earlier and more pronounced hollowing. If your parents or grandparents had prominent under-eye hollows, you are more likely to develop them, and potentially at a younger age. Hereditary hollowing can sometimes be apparent even in the twenties.
Weight loss, particularly rapid or significant weight loss, can dramatically worsen under-eye hollowing. Facial fat is lost during weight loss along with body fat, and because the under-eye area has relatively little fat to begin with, even modest facial fat reduction can make the hollows considerably more prominent. This is a common concern among people in Ireland who have lost weight for health reasons but are unhappy with the facial changes that accompany it.
Lifestyle and environmental factors influence the severity and speed of under-eye changes. Chronic sleep deprivation causes fluid redistribution and dilation of blood vessels beneath the eyes, which can emphasise hollowing and darken the under-eye area. Allergies (very common in Ireland, particularly hay fever) cause rubbing and inflammation that can darken and thin the under-eye skin over time. Excessive alcohol consumption causes dehydration and inflammation, temporarily worsening under-eye appearance.
Medical conditions can occasionally contribute. Thyroid disorders, iron deficiency anaemia, and autoimmune conditions can affect the under-eye area. If your hollowing has developed rapidly, is accompanied by other symptoms, or seems disproportionate to your age, a medical evaluation is advisable before pursuing cosmetic treatment.
Types and Severity Levels
Under-eye hollowness presents along a spectrum, and accurate assessment of severity guides appropriate treatment selection.
Grade 1 — Mild hollowing with subtle shadowing. At this early stage, the tear trough is barely visible in direct light but becomes apparent in certain lighting conditions or when the face is tilted. There may be a faint shadow beneath the inner eye. The contour from lower lid to cheek is slightly less smooth than in youth, but there is no obvious groove. This stage is often first noticed in photographs rather than in the mirror. Many people in their late twenties to early thirties fall into this category.
Grade 2 — Moderate hollowing with visible groove. A clear depression is visible along the tear trough, creating a noticeable transition between the lower eyelid and the cheek. The shadow is apparent in most lighting conditions and contributes to a tired appearance. The skin may be slightly thinner and more translucent, with blood vessels potentially visible. This is the most common presentation among people in their late thirties to forties seeking treatment in Ireland.
Grade 3 — Significant hollowing with deep tear trough. A deep, well-defined groove extends from the inner eye corner, potentially reaching toward the mid-cheek. The shadow is pronounced, the eyes appear sunken, and there may be associated changes including a visible bulge below the groove (where descended fat has collected), noticeable skin thinning, and crepey texture. The overall effect is significant facial ageing around the eyes. This presentation is more common from the late forties onwards.
Grade 4 — Severe hollowing with multiple associated changes. Deep tear troughs combined with significant skin laxity, pronounced fat pad descent (eye bags), extensive skin thinning, and crepey or heavily pigmented skin. At this severity, non-surgical treatments alone may have limited impact, and lower blepharoplasty (surgical eyelid correction) may need to be considered, either alone or in combination with non-surgical approaches.
Bilateral versus asymmetric presentation. Some people have roughly equal hollowing beneath both eyes, while others show more pronounced hollowing on one side. Asymmetric hollowing is common and may relate to habitual sleeping position (side sleeping compresses one side more than the other), underlying facial bone asymmetry, or uneven fat distribution. Treatment plans should account for and address asymmetry.
Treatment Options Available in Ireland
A range of non-surgical treatments is available for under-eye hollowness in Ireland, delivered by practitioners registered with the Medical Council of Ireland, the Dental Council, or NMBI. The under-eye area is considered an advanced treatment zone, and practitioner selection is particularly important here.
Tear trough filler is the most well-known treatment for under-eye hollowness. A small volume of hyaluronic acid dermal filler — typically 0.5ml to 1ml per side — is injected into the tear trough to restore volume, smooth the depression, and reduce the shadow effect. Specific HA fillers designed for this area are softer, less hydrophilic (attract less water), and less prone to swelling than fillers used elsewhere on the face. The treatment is performed using a needle or, more commonly, a cannula (a blunt-tipped instrument that reduces bruising and minimises the risk of vascular injury).
When performed by a skilled practitioner, tear trough filler can produce dramatic improvement — eliminating the tired, sunken appearance and creating a smoother, more youthful contour from eyelid to cheek. Results typically last twelve to eighteen months. However, this is an advanced injection area where complications, while uncommon, can be more consequential than in other facial areas. Proper patient selection, appropriate product choice, and experienced technique are all critical.
Polynucleotides are emerging as an excellent treatment for the under-eye area, particularly for patients who may not be ideal candidates for filler. Polynucleotide therapy involves injecting purified DNA fragments that stimulate fibroblast activity, promote collagen and elastin production, and improve skin quality from the cellular level. In the under-eye area, polynucleotides can improve skin thickness, hydration, and elasticity, reducing the visibility of hollowing and improving dark circles caused by thin, translucent skin. A course of two to four sessions, spaced three to four weeks apart, is typically recommended.
Skin boosters containing hyaluronic acid can improve under-eye skin quality without adding significant volume. Skin boosters hydrate the dermis, improve light reflection, and stimulate modest collagen production. They are well-suited for mild hollowing where the primary concern is skin quality and subtle shadowing rather than deep structural volume loss.
PRP (platelet-rich plasma) therapy uses the patient's own blood, processed to concentrate growth factors, which is then injected beneath the under-eye skin. PRP treatment stimulates collagen production, improves skin quality, and can reduce pigmentation. It is a good option for patients who prefer an autologous (using their own biological material) approach and can be particularly effective for dark circles with a pigmentation component.
Radiofrequency and microneedling combination devices can improve under-eye skin quality by stimulating collagen production and mildly tightening the skin. While these treatments do not restore volume, they can improve skin texture, reduce fine lines, and create a modest tightening effect that makes mild hollowing less apparent.
Mid-face volume restoration is an important indirect treatment for under-eye hollows. In many cases, the appearance of under-eye hollowing is worsened by cheek volume loss — when the cheeks deflate, the transition from lower eyelid to cheek becomes more abrupt, accentuating the tear trough. Restoring cheek volume with dermal fillers can significantly improve the under-eye appearance, sometimes reducing or eliminating the need for direct tear trough treatment. This is related to the broader concern of facial loss of volume.
Medical-grade eye care prescribed by an aesthetic practitioner serves as an essential complement to professional treatments. Medical-grade skincare products formulated for the periorbital area — containing retinoids, peptides, vitamin K, caffeine, and niacinamide — can improve skin thickness, reduce pigmentation, and support the results of in-clinic treatments.