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.
Dog eye boogers are a natural way of the eyes to wash out dirt and debris. It is not possible to prevent them. Dog eye boogers can reduce visibility (courtesy of petplace.com)