Why do your under-eyes look darker when you don't sleep?

When you're short on sleep, it's common for the area under your eyes to look darker and duller. In one study, faces were rated as more tired, and their under-eyes as darker, after sleep deprivation (Sundelin et al., 2013). Most of the time this is thought to be a temporary impression where puffiness, paleness, and visible blood vessels overlap, and it eases once you've rested. Pigmented dark circles, though, don't fade with sleep alone. So it helps to prioritize sleep, sun protection, and gentle hydration first, and think of active ingredients as a later step.

Why do under-eyes look darker on little sleep?

When you sleep poorly, your complexion tends to look paler overall. The skin under the eyes is thin, so when it turns pale the blood vessels beneath are thought to show through more, reading as dark or bluish. Add the mild puffiness many people notice in the morning, and the small shadows it casts make the area look darker still. Faces after a night of almost no sleep were judged to have darker under-eye circles, paler skin, and more swollen eyes than after normal sleep (Sundelin et al., 2013). Under-eyes darkened by lost sleep are an impression of paleness, show-through, and puffiness rather than pigment, so start with sleep.

Is it a real dark circle, or just tiredness?

Telling them apart is simpler than it sounds. If the shadow lifts noticeably after a good night's sleep or a restful weekend, it's likely a temporary, sleep-related impression. A brown tone that stays put under the eyes even after rest may be pigment that has built up over time, or a vascular type you were born with. Because the right approach depends on which one you have, it helps to read how to tell pigmented and vascular circles apart.

What besides sleep darkens the under-eye?

If your under-eyes stay dark even when you're well rested, it's worth looking at other causes. Sun exposure can deepen pigment around the eyes, so everyday sun protection is a foundation of under-eye care. Rubbing the area because it feels dry or itchy can leave behind irritation and color, too. Ingredients like caffeine can help temporarily with puffiness or the vascular type, though they're more of a support than a fix. If you're curious, see our note on caffeine eye serums and dark circles.

In short, sleep and sun protection come before ingredients

After lost sleep, under-eyes looked darker and skin paler (Sundelin et al., 2013), a temporary impression that eases once you've rested. The eye area is thin, so it's safer to steady the basics before layering on several new ingredients. Sun protection slows pigment from deepening, and light hydration keeps the area comfortable. Add eye-area ingredients once sleep, sun protection, and light hydration are in place.

One thing today

• If a tired look keeps coming back, start by making your sleep more regular. After a night of almost no sleep, under-eyes looked darker than after normal sleep (Sundelin et al., 2013). The morning after a good night, check in the same light whether the shadow has lifted. If a brown tone stays or keeps deepening even with good sleep, see a dermatologist.
• When your under-eyes look puffy in the morning, press something cool over them gently to settle it. Cold pressing hasn't been tested in a trial. See whether the puffiness eases within a few minutes. If it lasts all day or only one side swells, see a doctor.
• Take daytime sunscreen all the way to the under-eye area. Sun protection is a common way to keep under-eye pigment from deepening. Check in the mirror before going out that you covered the under-eyes. If your eyes sting, switch to a gentler formula around the eyes.