thumb|right|Rheum from a cat's eyes

Rheum (; 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). Rheum dries and gathers as a crust in the corners of the eyes or the mouth, on the eyelids, or under the nose. 'sleepy-seeds', 'sleepy buds', 'sleepy sand', 'eye boogers', 'eye goop', 'sleepies', or 'eye gunk'. 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.

Medical conditions

A number of conditions can increase the production of rheum in the eye. In the case of allergic conjunctivitis, the buildup of rheum can be considerable, preventing the patient from opening one or both of the eyes upon waking without prior cleansing of the eye area. The presence of pus in an instance of heavy rheum buildup can indicate dry eye or conjunctivitis, among other infections.

See also

  • Mucopurulent discharge

References

  • Why Is There Gunk in My Eye? at WebMD