Dark circles: work out the cause before you buy a cream

Not one problem, but several

What looks like a single dark circle is usually one or more of these: extra pigment in the skin under the eye, thin skin that lets the blood vessels underneath show through as a bluish or purple tone, and shadow cast by puffiness or by a hollow (the tear trough) between the lower lid and the cheek. A review of the condition describes all three, and notes that many people have a mix.

The cause matters because the fix is different for each one.

A quick way to tell

Look in a mirror facing a window, then tilt your face slowly up toward the light. A circle that fades as the light fills the area is mostly shadow from a hollow or puffiness. Brownish color that stays put is more likely pigment. A bluish or purplish tone where the skin is thinnest points to blood vessels showing through.

This is a rough guide, not a diagnosis — but it is better than choosing a product at random.

Pigment: sun protection and patience

Pigment-type circles are common in darker skin and often run in families. They darken with sun and with rubbing. Daily sunscreen that reaches the under-eye area, sunglasses, and not rubbing the eyes are the foundation. Gentle brightening ingredients can help over months, but the skin there is thin and reactive, so introduce anything new slowly and stop if it stings.

Thin skin and visible vessels

When vessels show through, the goal is to make the skin a little less translucent over time and to avoid making the vessels more prominent. Retinoids used carefully around — not on — the eye area can have this kind of long-term effect, but they irritate easily here. Cold compresses can make the color less obvious in the short term.

Puffiness, sleep and allergies

In a controlled study, people photographed after sleep deprivation were rated as having darker circles and more swollen eyes than after a normal night, so sleep is a real factor and not a cliché. Fluid tends to collect under the eyes overnight, especially after salty food or alcohol, and allergies that make you rub your eyes darken the area over time. Treating hay fever or eczema around the eyes often helps the circles too.

When it's a hollow

A shadow from a tear-trough hollow is structural, and no cream changes structure. In-clinic options such as hyaluronic acid filler exist, but the under-eye area is one of the more delicate places to inject. If you consider it, see an experienced medical injector and ask about risks, downtime and how it can be reversed.