Rheum (/ruːm/; from Greek: ῥεῦμα rheuma 'a flowing, rheum') is a thin mucus naturally discharged from the eyes, nose, or mouth, often during sleep (contrast with mucopurulent discharge).[1][2][3] Rheum dries and gathers as a crust in the corners of the eyes or the mouth, on the eyelids, or under the nose.[3] It is formed by a combination of mucus (in the case of the eyes, consisting of mucin discharged from the cornea or the conjunctiva), nasal mucus, blood cells, skin cells, or dust.
Rheum from the eyes is particularly common. Dried rheum near the eyes is commonly called 'sleep',[4] ‘sleet’, 'sleepy-seeds',[5] 'sleepy buds',[5] 'sleepy bugs', 'sleepy sand',[6] 'sleepy winks', 'eye boogers',[6] 'eye goop',[6] 'sleepy dust',[6] 'sleepies',[7] 'eye gunk',[7] 'eye crust', 'sleepy men', 'crusties', 'dozy dust', 'eye globs', or 'sleepy dirt'.[8] When the individual is awake, blinking of the eyelid causes rheum to be washed away with tears via the nasolacrimal duct. The absence of this action during sleep, however, results in a small amount of dry rheum accumulating in corners of the eye. A parent or pet owner may notice the collection of rheum on children and pets they care for.
- ^ "Rheum". Merriam-Webster. Retrieved 11 November 2020.
- ^ Amodio, Aimee."Where Do Eye Boogers Come From?", Families.com blog
- ^ a b Hiskey, Daven. "What the 'Sleep' In Your Eyes Is", Today I Found Out, 23 February 2011.
- ^ Shorter Oxford English Dictionary. Oxford University Press. 2008. ISBN 978-0-19-920687-2.
- ^ a b Eric Partridge, Paul Beale, ed., A Dictionary of Slang and Unconventional English, 8th edition, 1984, s.v.
- ^ a b c d Nierenberg, Cari (14 September 2011). "Are yours crusty or wet? The truth behind eye boogers (ew)". NBC News.
- ^ a b "Did you know that the real name for eye sleepies is rheum, and it doesn't only come from your eyes?". Office for Science and Society.
- ^ "The Eye Crud, The Sleepy Dirt Poem by Jeff Gangwer". Poem Hunter. 18 March 2016.