Yeah, in fact, Steven Jay Gould wrote a great article on how "As Mickey became increasingly well behaved over the years, his appearance became more youthful. Measurements of three stages in his development revealed a larger relative head size, larger eyes, and an enlarged cranium--all traits of juvenility." As he puts it, "Humans feel affection for animals with juvenile features."

full article: http://www.monmsci.net/~kbaldwin/mickey.pdf

This would explain the glut of sites such as cuteoverload.com

I once took a Psychology course which had another explanation for the large eyes. Apparently, when humans are sexually aroused, their pupils get larger. This makes people with larger pupils more sexually appealing, leading to all kinds of tricks to making your pupils larger (for example, candlelit dinners; also, in some older civilizations, women used to use eyedrops to make their pupils larger).

All of this leads to people thinking larger pupils look better, and in the case of small cartoon characters, look cuter.

The eyedrops you refer to are belladonna, Italian for 'beautiful woman'.

The intro from the Wikipedia entry ( http://en.wikipedia.org/wiki/Atropa_belladonna ) says:

"It has a long history of use as a medicine, cosmetic, and poison. Before the Middle Ages, it was used as an anesthetic for surgery, the ancient Romans used it as a poison (the wife of Emperor Augustus and the wife of Claudius both used it to murder contemporaries) and predating this it was used to make poison tipped arrows."

and

"Drops prepared from the belladonna plant were used to dilate women's pupils, an effect considered attractive."

And all of a sudden I want to give my wife a candle-light dinner.