What actually causes dark circles and why most people treat the wrong one

01The types of dark circle

A 2021 evidence-based review classifies infraorbital dark circles by cause: shadowing from structural hollowing, vascular colour from vessels visible through thin skin, idiopathic hyperpigmentation, post-inflammatory hyperpigmentation, and constitutional types.

The distinction is practical, not academic. Each sits in a different layer — one is shape, one is colour, one is skin thickness — so what helps one does little for another.

In practice many people carry more than one type at once. Correcting a single component then produces partial improvement, which is experienced as 'it didn't work' even when the procedure did exactly what it should.

02Telling them apart

Use this to arrive at your consultation with better questions — not to self-diagnose.

03Why filler is not the universal answer

Filler works on shape. It restores a hollow, the shadow shortens, and the area looks brighter. That mechanism genuinely works for the shadowing type.

When the darkness comes from pigment in the skin, or from vessels seen through thin skin, added volume changes none of it. The result is a smoother but equally dark under-eye — the source of 'I had it done and it's still dark' even though the injection succeeded on its own terms.

A 2026 review describes the periorbital region as among the most challenging sites in aesthetic medicine: thin dermis, complex vascularity, and susceptibility to oedema and contour irregularity. The specific risks named include the Tyndall effect — a bluish-grey show-through when product sits too superficially — and malar oedema.

Precision of depth and amount matters more than quantity.

04Bags versus hollows

These sit next to each other and get lumped together, but the mechanisms are opposite: a hollow is a depression, a bag is a protrusion — usually orbital fat pushing forward as the retaining structures weaken with age.

Where a prominent bag already exists, adding volume can make the area look fuller rather than smoother. Assessment must establish which is the dominant feature first.

The commonly missed point is that a 'bag' is not one component. Lower-eyelid surgical reviews distinguish patients with prominent fat-pad herniation and no excess skin from those who also need skin addressed — which is precisely why the approaches differ.

That split matters here, because different technologies answer different components.

Energy-based procedures — radiofrequency, or focused ultrasound — work on skin quality and firmness by stimulating collagen in the skin layers. They have a genuine role where laxity or thin skin is the component.

They do not reposition or reduce fat that has herniated forward from the orbit; that sits in a different layer with a different mechanism.

So where the bag is driven mainly by orbital fat, the mechanism-matched answer is assessment by an oculoplastic or plastic surgeon — not injectables, and not an energy device. Where the dominant component is lax skin, a tightening procedure becomes reasonable.

Many people have both in differing proportions, and only examination establishes which.

05Cautions and questions to ask

The periorbital vasculature connects with the eye's own circulation, so injection here belongs with a physician who knows the anatomy. Severe pain, blurred or altered vision, or blotchy skin colour change after treatment requires immediate contact — not waiting to see.

One more practical point: some under-eye treatments require repeated sessions. In one imaging study of periorbital pigmentation treatment, a number of participants withdrew mid-course because they could not tolerate the discomfort.

Tolerance is worth discussing honestly before starting.

This article is general information, not a diagnosis or individual treatment advice. Some under-eye darkening relates to other health conditions such as chronic allergy or anaemia, which need medical assessment.

• Which type do I have — and do I have more than one?
• If mine is pigmented or vascular, how much would volume correction actually achieve?
• If swelling persists or bluish-grey show-through appears, how is it corrected and how long does that take?
• Should any underlying condition be checked first, such as chronic allergy?
• How many sessions, and when is the review appointment?