Bags or Circles Under The Eyes

There are actually two conditions at work:

1. Swelling or “bags” under the eyes
2. Dark circles under the eyes

Both are associated with being tired, for some reason.

The “bags” are just fat deposits. They grow a bit with age, and the muscles can’t support them as well, so they drop and appear more prominent.

The part about them being bigger when you haven’t had much sleep is most likely a myth. They’re naturally bigger in the morning, since lying flat for eight hours allows fluid to pool there. But the only thing that will make them bigger from day-to-day is fluid retention (salty foods will affect this), and rubbing them due to eye irritation.

Dark circles under the eyes might just be shadows caused by bags under your eyes. So the two “conditions” could be inadvertently related.

There’s an official name for the darkness under the eyes: Periorbital Hyperpigmentation. Some people are just naturally pre-disposed to it.

Another theory says that the skin in this area is naturally thinner, so any pooling of blood under the eyes would cause that area to appear darker. Anything that drives more blood to your eyes – like eye strain or irrational (perhaps dry eyes caused by poor sleep) – can manifest as darker patches under the eyes. Some of these conditions might be associated with lack of sleep.

Also, there might be a slight psychological trick of association at work here. Women traditionally conceal bags or darkness under their eyes with makeup. If they do not apply makeup, the bags or darkness is more prominent. And not applying makeup in the morning is often associated with over-sleeping and rolling out of the bed at the last minute. Thus, we might simply have a mental correlation with the two variables – a woman without makeup is sometimes described as looking “tired,” when really we’re just extrapolating from whether or not we believe she had time to apply makeup in the morning.

So, this is not a “myth,” but there’s not a direct correlation between lack of sleep and these conditions.

Here’s what’s more likely –

The existence of bags under the eyes has correlation with the amount of time between when a person wakes up, and when they are seen in public. If this is a short timespan, then they (1) likely didn’t apply makeup to minimize the bags, and (2) they haven’t been vertical long enough for the swelling to diminish.

Since shortness of this timespan is also likely correlated with someone not getting enough sleep (e.g. they overslept because they stayed out late or didn’t sleep well), this correlation carries over to us assuming the person is tired, and, ultimately, to us associating eye bags with lack of sleep.