Somebody was saying it’s when you can see the white over both the top and the bottom of the irises, it’s crazy time.
Sanpaku Eyes (Three Whites):
If the sclera is visible above or beneath the iris, making the iris bounded by sclera on three sides, it is called Sanpaku Eyes or Three Whites Eyes. There are two kinds of Three Whites Eyes: Upper-Three Whites (sclera is above the iris) and Lower Three-Whites (sclera is beneath the iris). The latter is most seen. Looking terrifying, this kind of people is usually adventurous, cool, cunning, and venomous. They have a strong personality, would like to sacrifice anything to gain the aim. So, many of them have a great achievement in society. Better dont challenge this kind person because he is touchy, violent and suspicious.
Four-Whites Eyes:
If the sclera is visible both above and beneath the iris, making the iris bounded by sclera on four sides, that is Four-Whites Eyes. Compared with the people of Sanpaku Eyes, the Four-Whites Eyes people have much stronger personality and more destructive and vindictive. They are cruel and poisonous, at the same time rather difficult to approach.