Notes and References. 1  U.S. Senate: Reference Home > Glossary > Christmas tree bill. 2  Lardner, George (1966) The Day Congress Played Santa: A Look at the Christmas Tree Bill, Washington Post, 25 December, p. A1, A10. 3  Shribman, David (1983) It Began as a Rather Ordinary Piece of Legislation, New York Times, 9 November, p. A22.
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, most notably in children.
Small amounts of eye mucus is not usually a problem. Eye mucus is very similar to nasal mucus. The nasal cavity is also lined by mucous membranes and when this mucus is hardens, it forms crusts that we commonly refer to as boogers. However, crusted eye mucus like nasal mucus poses no significant problem to the eye.