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Why do our eyes get puffy when we cry?

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Y: Don, your eyes are all swollen and puffy. Have you been crying?

D: (INDIGNANT) Of course not, Yael. I'm a man!

Y: Are you sure you haven't been watching soaps again?

D: No. These tears that you're seeing are the very same ones that keep our eyes moist and comfortable, and wash out bits of dust and debris.

Y: Hmm! are you sure? Those basic tear secretions are produced in the conjunctiva, the membrane that coats the entire surface of the eye.

D: So?

Y: So these basic secretions don't overflow like the tears associated with emotional crying. Those tears are produced by the lachrymal gland, located in the upper, outer corner of our eyelids, and not only are they much more watery than basic tear secretions, but there are usually so many of them that they overflow and spill down your cheeks and drain through tiny ducts into your nose.

D: Not my nose--I don't cry.

Y: I didn't mean you personally.

D: Okay, so let's say someone--like a friend of a friend, but not me--has been crying. Why would his eyes get all puffy?

Y: Like yours are now?

D: Hypothetically!

Y: Well, because emotional tears are more watery, they're less salty than basic tear secretions and the tissue in your eye. So, through the process of osmosis, the water moves into the saltier ocular tissues, which makes them swell up. And then there's all that furtive eye rubbing your "friend" does to hide his tears, which inflames his eyes even further. Still, even though it looks bad, the puffiness and irritation will eventually go away.

D: Well, that was easy. I guess I'll go back to watching "Love Story."

Y: Don't forget the Kleenex.

Crying Baby

Basic tear secretions are produced in the conjunctiva, the membrane that coats the entire surface of the eye. (Yoshihide Nomura/flickr)

Did you know there's a difference between when you've been crying for emotional reasons and if your eye gets a bit watery?

Those basic tear secretions that keep our eyes moist and comfortable and wash out bits of dust and debris are produced in the conjunctiva, the membrane that coats the entire surface of the eye.

These secretions don't overflow like the tears associated with emotional crying. Emotional tears are produced by the lachrymal gland, located in the upper, outer corner of our eyelids. Not only are they much more watery than basic tear secretions, but there are usually so many of them that they overflow and spill down your cheeks and drain through tiny ducts into your nose.

So then, why do our eyes get all puffy from crying?

Well, because emotional tears are more watery, they're less salty than basic tear secretions and the tissue in your eye. So, through the process of osmosis, the water moves into the saltier ocular tissues, which makes them swell up. And then there's all that furtive eye rubbing we sometimes do to hide our tears, which inflames the eyes even further. Still, even though it looks bad, the puffiness and irritation will eventually go away.

Just make sure you don't forget the Kleenex.

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