If you look at the old ass anime, the real real old stuff, it takes a lot of characteristics from Walt Disney's drawings. Yes, the original style of anime was influenced by western art. That's where the big eyes come from. Over the years, Disney cartoons have toned down the eyes, making it known almost entirely as an Anime characteristic. The more you know.
Well, it's the style that the Japanese usually draw the characters. The eyes drawn big is the identity of the Japanese. Another reason is to show the emotions of the character. Because the eyes can reflect how a person feels, so when the eyes are drawn big, it is easier to capture how the person is feeling so that the audience can relate to it.
http://answers.yahoo.com/question/index?qid=20090102011759AADhenR
http://answers.yahoo.com/question/index?qid=20090102011759AADhenR