LOL, I really think you are humorous when you are asking this question, because you know both Chinese and Japanese are Asian and if you really want to know the difference between their eyes, I think there is just little difference. For example, from the size of the eyes, you are easily to know that the eyes from Chinese are bigger than the eyes from Japanese because the face of Chinese are a little longer while the face of Japanese are rounder than the Chinese. On the other hand, as to the shape of the eyes, if you look carefully, you will find that the eyes of Chinese are slant up, while, the eyes of Japanese are slant down. Of course, the differences I mentioned above are really hard to notice. You can get to know it with your carefulness.