What are "Sanpaku Eyes"?

I only recently found out about an insane Japanese superstition called Sanpaku Eyes. Apparently the Japanese have a great way of figuring out a hell of a lot about you based on your eyes alone. Also known as "the three whites", Sanpaku eyes occur when the white of the eyes is naturally visible either above or below the iris (coloured part) as well as the sides. This is where it gets interesting...