# What is the medical term for “sleep crust” **URL:** \ **Category:** Factual Questions\ **Created:** [November 21, 2000, 7:42am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102 "2000-11-21T07:42:13Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [November 21, 2000, 7:42am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/1 "2000-11-21T07:42:13Z")
I’m talking about the dry stuff you find at the corners of your eyes when you wake up in the morning. I sometimes find it sticking to my eyelashes as well. If I get to it before it dries completely, it is a sticky liquid, with the consistency and color of phlegm. It’s not a uniquely human phenomenon. I’ve found the stuff at the corners of my dogs’ eyes and my cats’ eyes (back when I had cats). I recall coming across the medical term for it several years ago, but I can’t find it now. As long as we’re at it, is it really dried tears? Most people seem to assume so, but I’m not sure. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [November 21, 2000, 7:44am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/2 "2000-11-21T07:44:53Z")
Boogerus Nocturnus? ---
**Author:** ![evilbeth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/evilbeth/32/2268_2.png) [@evilbeth](https://boards.straightdope.com/u/evilbeth)\ **Post date:** [November 21, 2000, 7:51am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/3 "2000-11-21T07:51:36Z")
Well, [here’s](http://www.cae.wisc.edu/~schmolli/old_homepage/dear_ed/letters/0x10.html) a different theory on the origins of said eye leakage… ---
**Author:** ![evilbeth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/evilbeth/32/2268_2.png) [@evilbeth](https://boards.straightdope.com/u/evilbeth)\ **Post date:** [November 21, 2000, 7:53am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/4 "2000-11-21T07:53:45Z")
How about [Ocumuculosis](http://www.kkcltd.com/paw/pit_archive/edition5/jingle.html)? ---
**Author:** ![evilbeth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/evilbeth/32/2268_2.png) [@evilbeth](https://boards.straightdope.com/u/evilbeth)\ **Post date:** [November 21, 2000, 7:57am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/5 "2000-11-21T07:57:16Z")
But seriously, I think it is called “rheum.” ---
**Author:** ![andygirl](https://avatars.discourse-cdn.com/v4/letter/a/a9adbd/32.png) [@andygirl](https://boards.straightdope.com/u/andygirl)\ **Post date:** [November 21, 2000, 8:12am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/6 "2000-11-21T08:12:10Z")
It’s called vitreous humor. Cite? One of Neil Gaiman’s comics. Odd source, but I’ve never known him to be wrong. ---
**Author:** ![Meephead](https://avatars.discourse-cdn.com/v4/letter/m/b782af/32.png) [@Meephead](https://boards.straightdope.com/u/Meephead)\ **Post date:** [November 21, 2000, 8:27am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/7 "2000-11-21T08:27:23Z")
> [@](#): > > \*Originally posted by andygirl \* > \*\*It’s called vitreous humor. \*\* I thought vitreous humor was the stuff inside your eyball… Of course, if it leaks out while you are sleeping, then I guess that would explain it. ---
**Author:** ![Astroboy14](https://avatars.discourse-cdn.com/v4/letter/a/df705f/32.png) [@Astroboy14](https://boards.straightdope.com/u/Astroboy14)\ **Post date:** [November 21, 2000, 10:16am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/8 "2000-11-21T10:16:32Z")
I prefer the term “eye boogers” ---
**Author:** ![Uniball](https://avatars.discourse-cdn.com/v4/letter/u/e5b9ba/32.png) [@Uniball](https://boards.straightdope.com/u/Uniball)\ **Post date:** [November 21, 2000, 10:57am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/9 "2000-11-21T10:57:39Z")
> [@](#): > > \*Originally posted by andygirl \* > \*\*It’s called vitreous humor. > > Cite? One of Neil Gaiman’s comics. Odd source, but I’ve never known him to be wrong. \*\* He said that we all can fly. He was wrong. ---
**Author:** ![LazarusLong42](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@LazarusLong42](https://boards.straightdope.com/u/LazarusLong42)\ **Post date:** [November 21, 2000, 3:45pm UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/10 "2000-11-21T15:45:47Z")
Okay… I can’t find a source for the actual medical term for that crust. My suspicion is that, because it’s not pathological–I mean, you can pretty much just wipe it away–it may not have an official term. It’s produced by sebaceous glands in your eyelids called the Meibomian glands. These glands produce an oily layer which prevents your tears from evaporating as quickly as they would without it, thus causing you to have to blink quite a bit less. That oily layer–not to mention the lachrimal (tear) layer itself–continues to be produced when you’re asleep. The tears evaporate, but some of the oily layer, as well as salts in your tears, do not evaporate. They mix together to form that crust. Aren’t you glad you know now? 🙂 LL ---
**Author:** ![Fiver](https://avatars.discourse-cdn.com/v4/letter/f/e274bd/32.png) [@Fiver](https://boards.straightdope.com/u/Fiver)\ **Post date:** [November 21, 2000, 7:45pm UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/11 "2000-11-21T19:45:19Z")
**andygirl** : > [@](#): > > It’s called vitreous humor. > > Cite? One of Neil Gaiman’s comics. Odd source, but I’ve never known him to be wrong. He wasn’t wrong, **andygirl** , but you misunderstood him. The vitreous humor is the fluid that fills the _inside_ of your eyeballs. There’s also the aqueous humor, a more watery fluid, that fills the space between your lens and some other membrane. Eye-boogies, whatever they are, have nothing to do with either humor. ---
**Author:** ![andygirl](https://avatars.discourse-cdn.com/v4/letter/a/a9adbd/32.png) [@andygirl](https://boards.straightdope.com/u/andygirl)\ **Post date:** [November 21, 2000, 7:53pm UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/12 "2000-11-21T19:53:27Z")
That’s what I get for posting at three in the morning after writing a paper, isn’t it… \ ---
**Author:** ![absoul](https://avatars.discourse-cdn.com/v4/letter/a/bc8723/32.png) [@absoul](https://boards.straightdope.com/u/absoul)\ **Post date:** [November 21, 2000, 8:08pm UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/13 "2000-11-21T20:08:41Z")
I believe it would depend on the liquid that has dried on the eyelid. ---
**Author:** ![Mr.Blue\_Sky](https://avatars.discourse-cdn.com/v4/letter/m/d26b3c/32.png) [@Mr.Blue\_Sky](https://boards.straightdope.com/u/Mr.Blue_Sky)\ **Post date:** [November 21, 2000, 10:47pm UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/14 "2000-11-21T22:47:48Z")
As a kid, we always called it “eye jam”. ---
**Author:** ![beagledave](https://avatars.discourse-cdn.com/v4/letter/b/6de8d8/32.png) [@beagledave](https://boards.straightdope.com/u/beagledave)\ **Post date:** [November 22, 2000, 12:34am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/15 "2000-11-22T00:34:17Z")
wtf…you mean there IS no Mr. Sandman? …grrrr ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [November 22, 2000, 1:50am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/16 "2000-11-22T01:50:26Z")
Rheum for one more? ---
**Author:** ![evilbeth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/evilbeth/32/2268_2.png) [@evilbeth](https://boards.straightdope.com/u/evilbeth)\ **Post date:** [November 22, 2000, 4:40am UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/17 "2000-11-22T04:40:10Z")
> [@](#): > > \*Originally posted by Dr\_Paprika \* > \*\*Rheum for one more? \*\* Since no one commented when I posted the word, I’m guessing that no one thinks “rheum” is the answer! Fine, then! ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [November 22, 2000, 3:30pm UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/18 "2000-11-22T15:30:31Z")
I dont get the crusts. Whew. If I did, I would think that I wasn’t eating properly or not drinking enough water or something. How about that drool sometimes when you nap? I wonder what that’s called? ---
**Author:** ![scratch1300](https://avatars.discourse-cdn.com/v4/letter/s/dfb087/32.png) [@scratch1300](https://boards.straightdope.com/u/scratch1300)\ **Post date:** [November 22, 2000, 3:38pm UTC](https://boards.straightdope.com/t/what-is-the-medical-term-for-sleep-crust/42102/19 "2000-11-22T15:38:36Z")
**evilbeth** , I agree with you. _Rheum_ it is. Another term I’ve heard – my dad told me his parents used to say it – is _slam_. I have no idea where they got this, but they were Irish. Is _slam_ still extant in Ireland as a synonym for eye-boogers?