# "Sleep" in your eyes

**URL:** <https://boards.straightdope.com/t/sleep-in-your-eyes/231554>\
**Category:** Factual Questions\
**Created:** [February 28, 2004, 12:51am UTC](https://boards.straightdope.com/t/sleep-in-your-eyes/231554 "2004-02-28T00:51:19Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Mr.Kobayashi](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@Mr.Kobayashi](https://boards.straightdope.com/u/Mr.Kobayashi)\
**Post date:** [February 28, 2004, 12:51am UTC](https://boards.straightdope.com/t/sleep-in-your-eyes/231554/1 "2004-02-28T00:51:19Z")

</div>

What is that stuff that forms in your eyes after periods of sleep?  
😕

---

<div class="post-metadata">

**Author:** ![Zenenofeus](https://avatars.discourse-cdn.com/v4/letter/z/f17d59/32.png) [@Zenenofeus](https://boards.straightdope.com/u/Zenenofeus)\
**Post date:** [February 28, 2004, 1:00am UTC](https://boards.straightdope.com/t/sleep-in-your-eyes/231554/2 "2004-02-28T01:00:00Z")

</div>

i can answer this i learned it this week in anatomy. Lacrimal Fluid(tears) normally produced to keep the eye clean and such is always flowing across your eye even when you sleep. Normally it will drain into you lacrimal puncta(the small little hole on the medial corner of your eye close to your nose) but since your eyes are closed this hole is blocked. When the water part of the lacrimal fluid evaporates during the night it leaves behind the salt, mucus and lysozmes(Spelling?) thus creating the residue that rub away in the mornings.

---

<div class="post-metadata">

**Author:** ![Mr.Kobayashi](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@Mr.Kobayashi](https://boards.straightdope.com/u/Mr.Kobayashi)\
**Post date:** [February 28, 2004, 1:03am UTC](https://boards.straightdope.com/t/sleep-in-your-eyes/231554/3 "2004-02-28T01:03:39Z")

</div>

Wow, that was quick. Thanks!

---

<div class="post-metadata">

**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\
**Post date:** [February 28, 2004, 4:17am UTC](https://boards.straightdope.com/t/sleep-in-your-eyes/231554/4 "2004-02-28T04:17:26Z")

</div>

Sometimes referred to as _matter_, though not in the physics sense. I had a nice case of conjectivitus one time and would wake up with my eyelids glued nicely shut. I asked my doc about it and he said, “Yeah. Matter’s a bitch.”

It handily explains the Beatles lyric, "_Yellow matter custard dripping from a dead dog’s eye_.

---

<div class="post-metadata">

**Author:** ![cw](https://avatars.discourse-cdn.com/v4/letter/c/71c47a/32.png) [@cw](https://boards.straightdope.com/u/cw)\
**Post date:** [February 28, 2004, 5:38am UTC](https://boards.straightdope.com/t/sleep-in-your-eyes/231554/5 "2004-02-28T05:38:17Z")

</div>

[QUOTE=It handily explains the Beatles lyric, "_Yellow matter custard dripping from a dead dog’s eye_.[/QUOTE]

Yeah, I have to wipe those eye boogers off my _living_ dog’s eyes several times a day.  
In a non-scientific sense, I think they are caused by dust, allergens, etc. I went on a hayride once and the next day my eyes were so mattered up I couldn’t open them without pulling the crust off my lashes. So I would think that it is just a biological eye clensing solution.