And while the cause of most of these sleep remnants is fairly obvious, the reason behind those sometimes-sticky, sometimes-crusty gobs of crud that can dot the lashes or cling to the corners of the eye is less clear.
Santa's Little Helper's initial appearance on The Simpsons was in the first episode of the series, Simpsons Roasting on an Open Fire, which aired on Dec. 17, 1989. Since then, he has become a recurring character.
The Simpsons has six main cast members: Dan Castellaneta, Julie Kavner, Nancy Cartwright, Yeardley Smith, Hank Azaria and Harry Shearer. Castellaneta voices Homer Simpson, Grampa Simpson, Krusty the Clown, Groundskeeper Willie, Mayor Quimby, Barney Gumble and other adult, male characters.