How do dark circles form?

Sometimes the skin itself becomes darker

Melanin is the pigment that gives skin its colour. Sun exposure can increase melanin production and darken the area beneath the eyes. Irritation from eczema, contact dermatitis or repeated rubbing can also leave extra pigment behind after the inflammation. This is called post inflammatory pigmentation. Darkness caused by pigment is different from darkness caused by a shadow, even though both get called dark circles. Pigment deeper in the skin responds poorly to topical treatments.12

Thin skin lets blood vessels show through

As skin beneath the eyes becomes thinner and looser with age, blood vessels become more visible. Blood pooling in the area can contribute to darkness too. Allergies can make eyes itch, and rubbing can damage small vessels and cause swelling and discolouration. Poor sleep can make the skin look paler, making vessels easier to see. Dark circles can appear blue, purple, brown or black, depending on natural skin colour.23

Sometimes the darkness is a shadow

Deep set eyes and hollows beneath the lower eyelids can cast shadows. These hollows, called tear troughs, can become more noticeable as tissue around the eyes loses volume with age. Significant weight loss can also change facial contours. Puffiness makes shadowing more noticeable, while dehydration can make eyes look sunken. A shadow can look like darker skin without being darker skin, which gives the category "dark circles" a fairly loose job description.14

Why can dark circles remain after enough sleep?

Inherited pigmentation and facial structure do not disappear after a good night's sleep. Dark circles can persist despite adequate sleep, so looking tired is not a reliable attendance record for bedtime. A family history makes dark circles more likely, and they affect people of all ages. They are more common in older people and people with darker skin tones. Sleep helps when fatigue contributes; it does not address every cause. Smoking and excessive alcohol use can also contribute.234

What helps depends on what creates the darkness

• For sun related pigmentation, use SPF 30 sunscreen daily and sunglasses with UV protection.
• For irritation, avoid rubbing and identify the allergen or irritant. Addressing that trigger can help the darkness lighten.
• For puffiness or prominent vessels, try a cold compress. Elevating your head with extra pillows at night can reduce fluid collecting beneath the eyes.
• For sleep related darkness, aim for at least seven hours of sleep each night.
• For immediate coverage, use concealer. Apply light reflecting concealer to the shadows rather than the puffy skin.

Pigment treatments and treatments for hollowing solve different problems. A dermatologist can assess whether darkness comes from pigmentation, vessels or facial structure. Lightening creams can help pigmentation, while fillers can address lost volume. Stronger products can irritate delicate eyelid skin; hydroquinone can cause irritation that creates further darkness. Procedures require an experienced clinician, and improvement can be partial. Many remedies sold for dark circles lack evidence that they work.123

When should you get dark circles checked?

Dark circles are usually a cosmetic issue rather than a medical problem. Contact a healthcare provider if darkness or swelling affects just one eye, or if swelling is excessive. Red, burning or swollen eyelids and blurry vision can be symptoms of an eyelid disorder rather than ordinary dark circles. An eye care specialist can examine the area and review your medical and family history.2456