Why Do We Get Dark Circles Under Our Eyes?

A short night and there they are in the mirror: shadows under the eyes that make you look more tired than you feel. Dark circles are one of the most common skin complaints, and a review of the medical literature shows they almost never have a single cause. Several features of the under-eye area stack together, and a bad night's sleep mostly turns up the contrast.

The thinnest skin you own

The skin of the lower eyelid is one of the thinnest in the body, with almost no fat underneath it. It sits directly on the orbicularis oculi, the muscle that closes the eye, and on a dense network of small blood vessels. Because the skin is thin and slightly transparent, it offers little camouflage: the dark red of muscle and the bluish tones of the vessels show through, and the whole area reads as darker than the rest of the face.

Shadow, not colour

Much of what looks like a dark circle is not pigment at all but shadow. The under-eye area has a natural hollow, the tear trough, and the shape of the bone and the ligaments beneath the skin decides how light falls on it. Dermatology research notes that overhead lighting makes these hollows look darker, while direct light can hide them. With age, the face loses bone and fat volume, the hollows deepen, and the shadow effect grows stronger.

Pigment and leaky vessels

In many people, especially with deeper skin tones, real pigment plays a part: extra melanin in the skin of the eyelids. Blood vessels can add their own colour too. When small vessels leak, haemoglobin breaks down into pigments such as hemosiderin and biliverdin, which leave brownish and greenish tones in the tissue. Fluid retention makes everything worse, because puffy eyelid skin catches more light and looks darker, which is why circles can seem worse in the morning or after a salty meal.

Where tiredness fits in

Lack of sleep does not create dark circles from nothing; it amplifies the existing machinery. Fatigue leaves skin paler and duller, so the underlying vessels stand out more, and fluid balance shifts make puffiness and shadows more noticeable. That is also why the circles fluctuate from day to day even when nothing else changes: one study of periorbital biopsies found daily variation in how dark the same skin looked, most likely from changes in fluid and light reflection.

Why one cream never fixes everyone

Because the causes differ, so do the fixes. Dermatologists treat pigmented circles differently from shadowed or vascular ones, using everything from topical caffeine and retinoids to lasers, fillers and surgery, chosen for the anatomy involved. For most of us, the honest summary is simpler: dark circles are anatomy showing through, and sleep, salt and lighting decide how loud they look today.

Facts checked: 21 October 2026

Sources: Vrcek, I., Ozgur, O., and Nakra, T. (2016). Infraorbital Dark Circles: A Review of the Pathogenesis, Evaluation and Treatment. Journal of Cutaneous and Aesthetic Surgery. PMC4924417.