Sunken Eyes & Hollow Under-Eyes Ireland — Causes and How to Treat Them

If you consistently look tired, drawn, or older than you feel — and concealer isn't really helping — hollow under-eyes are likely the reason. This is one of the most common concerns our doctors hear at Sisu Clinic locations across Ireland, and it's one of the most transformative to treat. In this post we explain exactly what causes sunken eyes, why they're so hard to conceal, and what actually works — from the doctor's perspective.

What are sunken or hollow under-eyes?

The area between your lower eyelid and upper cheek is called the tear trough. When this area loses volume — which happens naturally with age, genetics, or both — it creates a shadowed, hollow appearance beneath the eye. The skin here is the thinnest on the entire face, which is why even a small amount of volume loss shows up dramatically. That hollowed look casts a shadow that reads as dark circles, tiredness, and ageing — often all at once.
This concern has several overlapping names that patients use interchangeably: sunken eyes, hollow under-eyes, tear trough hollows, dark circles caused by hollowing, and under-eye bags caused by volume loss. They all describe variations of the same underlying issue — a lack of volume and support in the tear trough area.

What causes sunken eyes?

There are several reasons the under-eye area can develop a hollow or sunken appearance. Understanding the cause matters because it determines which treatment will actually help.
Age-related volume loss is the most common cause. From your mid-30s onward, the fat pads that sit beneath the skin of the eye area begin to reduce. The orbital septum — the membrane that holds these fat pads in place — weakens with age. As the fat reduces and descends, the eye socket appears larger and more hollowed. This is a natural process that affects almost everyone to some degree.
Genetics plays a significant role for many patients. Some people have naturally prominent tear troughs from a young age — not because of ageing, but because of the way their facial bone structure is positioned. If a parent or sibling has hollow under-eyes, there is a good chance you will develop the same.
Rapid weight loss can accelerate hollowing in the face, including under the eyes. When the face loses fat volume quickly, the skin that previously stretched over that volume becomes loose and the eye area can appear suddenly more sunken.
Lifestyle factors including chronic sleep deprivation, dehydration, smoking and high alcohol consumption all contribute to a tired, hollow appearance under the eyes — both through their effects on skin quality and by making blood vessels more visible through the thin eyelid skin.
Bone resorption is a less-discussed but important factor. As we age, the facial skeleton actually recedes slightly — particularly around the eye socket. This enlarges the orbital area and contributes to that deeply set, hollow eye appearance that no amount of filler can fully address without also supporting the skeletal structure.

Why is it so hard to conceal?

Several factors make tear trough hollows particularly resistant to makeup coverage. The shadow cast by the hollow is three-dimensional — it's caused by light falling into a depression, not by pigmentation in the skin. Concealer adds colour but does nothing to address the structural shadow. Overhead lighting (which is most artificial indoor lighting) makes hollowing more pronounced. Camera flashes and phone cameras capture the shadow even more dramatically than the naked eye sees it. And because the skin is so thin, even slight dehydration or a bad night's sleep makes the area look significantly worse.

What treatments actually work for sunken eyes in Ireland?

Tear trough filler — the most effective treatment
Hyaluronic acid dermal filler placed precisely in the tear trough is the gold-standard treatment for hollow under-eyes. A small amount of filler restores the lost volume beneath the eye, lifting the shadowed area and creating a smoother transition between the lower eyelid and the cheek. Results are immediate — most patients see a meaningful difference as they leave the clinic — and last 12 to 18 months.
At Sisu Clinic, tear trough filler is performed by medical doctors with specialist training in this specific area. The under-eye is one of the most anatomically complex and technique-sensitive areas for filler treatment — the skin is extremely thin, the vascular anatomy requires careful navigation, and the amount of filler used must be precise. Overfilling the tear trough creates the "pillow face" or puffy eye look that patients understandably want to avoid. Conservative, doctor-led placement is essential for a natural result.
The filler used is a medical-grade hyaluronic acid product specifically formulated for the tear trough — softer and more pliable than the products used for cheeks or jawline, which allows it to integrate naturally with the delicate tissue around the eye.

Polynucleotides for skin quality
For patients whose concern is primarily skin quality around the eye — thinness, crepiness, fine lines — rather than volume hollowing, polynucleotide injections are an excellent option. Polynucleotides stimulate the skin's own collagen and elastin production, improving skin thickness and quality over time. They work particularly well in the under-eye area because they improve the tissue itself rather than adding volume. Many patients benefit from a combination of tear trough filler for volume and polynucleotides for skin quality — your doctor will advise the right approach during consultation.

Anti-wrinkle injections for crow's feet
While anti-wrinkle injections don't address hollowing directly, they're often used alongside tear trough treatment to address the fine lines at the outer corners of the eyes (crow's feet). Treating both together — the tear trough and the crow's feet — delivers a more complete eye rejuvenation result.

What doesn't work

Eye creams, vitamin C serums, and caffeine patches can reduce puffiness temporarily and improve skin quality over time, but they cannot restore volume loss in the tear trough. No topical product adds structural support beneath the skin. They're worth using as part of a good skincare routine, but they won't fix a structural hollow.
Similarly, getting more sleep and drinking more water will reduce the lifestyle contribution to your tired eyes, but won't reverse age-related or genetic volume loss. If you've tried all the lifestyle changes and still look exhausted, structural treatment is likely the missing piece.

What to expect from tear trough filler at Sisu Clinic

Your treatment begins with a one-to-one consultation with a Sisu doctor, who will assess your under-eye area, discuss your goals, and confirm whether tear trough filler is the right treatment for your specific concern. Not everyone is a suitable candidate — patients with significant under-eye bags caused by orbital fat prolapse (fat protruding forward rather than hollowing) may be better served by a different approach, and your doctor will tell you honestly if that's the case.
If filler is appropriate, the procedure takes around 20 to 30 minutes. A numbing cream is applied beforehand. The filler is injected precisely at specific points in the tear trough using a very fine needle or cannula. You may notice mild swelling or bruising in the 24 to 48 hours after treatment — this is normal and settles quickly. The final, fully settled result is visible at 2 weeks.
Results typically last 12 to 18 months. Tear trough filler tends to last longer than lip filler because the area experiences less movement. Most patients treat annually or less frequently to maintain their result.

If you've been looking tired despite getting enough sleep, or struggling with hollow, shadowed under-eyes that concealer can't fix, book a free consultation at your nearest Sisu Clinic. Our doctors will assess your under-eye area, explain your options clearly, and recommend the right treatment for your specific anatomy — whether that's tear trough filler, polynucleotides, or a combination of both.