The reason why only Koreans in East Asia have slender eyes is that Koreans and Mongols belong to the same sub-race. According to relevant data, we can see from the historical context that Mongolians, including Koreans, all belong to the same sub-race and have the same ancestor. Koreans who have not had plastic surgery all have pie faces and slender eyes. East Asia is the abbreviation of East Asia, including China, Japan, South Korea, North Korea and Mongolia.