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.
There are four main causes of pink eye: Viruses; Bacteria; Allergens (like pet dander or dust mites) Irritants (like smog or swimming pool chlorine) that infect or irritate the eye and eyelid lining; It can be difficult to determine the exact cause of pink eye because some signs and symptoms may be the same no matter the cause.