Sleeping sand
Sleeping sand (also sleeping granules , sleep in the eyes , matzo , dream sand , eye stones , sleeping mud , mulehn (regional)) is the colloquial term for the accumulation of dried-up secretions from the glands of the eyelid ( eye butter or eye mucus ) that arise and become during sleep then collect at the edge of the eyelid.
Emergence
The front sections of the eyes must always be kept moist. This happens through tear fluid and mucus from the so-called goblet cells of the conjunctiva . The oily fluid of the Meibomian glands of the eyelid, which mixes with the tear fluid, reduces the evaporation of the moisture film.
During sleep, the fluid production in the eye is reduced, and residues of the fatty secretion of the meibomian glands can accumulate on the inner corner of the eye and crust over time. Because of their similarity in color and shape to sand , they are popularly referred to as "sleeping sand". There are also regional dialect names.
In addition to salts and proteins, sleeping sand consists of cell debris from white blood cells that die in the fight against (mostly harmless) bacteria .
After opening the eye, the feeling of a foreign body on the eye leads to rubbing the eye and removing the sleeping sand . You “rub the sleep out of your eyes”. A possible distribution of the secretion over the cornea of the eye leads to a blurring of the view until the secretion is removed, for example by blinking the eye .
Inflammation of the conjunctiva ( conjunctivitis ) and the edge of the eyelid ( blepharitis ) can lead to a pathological increase in mucus.
Others
Sleeping sand is sometimes associated with the legendary figure Sandman , for example in children's fairy tales .
Individual evidence
- ↑ Thomas de Padova: Why do we have “sand” in our eyes in the morning? In: Der Tagesspiegel , March 13, 2008. Retrieved August 16, 2016.
