→Subscribe for new videos every day! https://www.youtube.com/user/TodayIFoundOut?sub_confirmation=1 →How "Dick" came to be short for 'Richard': https://youtu.be/BH1NAwwKtcg?list=PLR0XuDegDqP2Acy6g9Ta7hzC0Rr3RDS6q Never run out of things to say at the water cooler with TodayIFoundOut! Brand new videos 7 days a week! More from TodayIFoundOut Green Coca-Cola... and 5 other everyday myths https://youtu.be/EmUo-TEP2FU?list=PLR0XuDegDqP1IHZBUZvKkPwkTr6Gr0OBO The Coming Banana Apocalypse https://youtu.be/pCpmtI6oDLM?list=PLR0XuDegDqP01NqW8KRpOy-_y2m6S2VEF In this video: “Sleep” is a type of “rheum”, which is the name for discharge from your nose, mouth or eyes during sleep. More specifically, eye rheum is known as “gound”. Gound is made up of a mixture of dust, blood cells, skin cells, etc. mixed with mucus secreted by the conjunctiva, as well as an oily substance from the meibomian glands. Want the text version?: http://www.todayifoundout.com/index.php/2011/02/what-the-sleep-in-your-eyes-is/ Sources: http://en.wikipedia.org/wiki/Sebaceous_gland http://en.wikipedia.org/wiki/Meibomian_gland http://familydoctormag.com/eyes/1429-what-causes-sleep-in-your-eyes-8-eye-health-questions.html http://en.wikipedia.org/wiki/Rheum http://www.livestrong.com/article/253984-what-is-the-sleep-in-your-eye/ http://ezinearticles.com/?Sleep-Eyes---Gross,-Why-Do-I-Have-So-Much-Gunk-in-My-Eyes-When-I-Wake-Up-in-the-Morning?&id=1352774 http://en.wikipedia.org/wiki/Mucin http://en.wikipedia.org/wiki/Allergic_conjunctivitis http://www.mothernature.com/Library/Bookshelf/Books/16/69.cfm http://www.contactlens.org.nz/extra1.aspx