This is a very common, but scientifically incorrect question. The fact is that the shape of the eyes that you call "narrow" is not the result of a single cause, but the consequence of a long-term evolutionary adaptation of many peoples of East Asia (not only Chinese, but also Koreans, Japanese, Mongols, and others) to certain environmental conditions. Here are the main scientifically supported factors that led to the formation of this feature: 1. Adaptation to cold and windy climate It is believed that the ancestors of modern East Asian peoples formed in cold, windy, and often snowy regions of Central Asia and Siberia. Protection from cold and dust: A narrower eye socket, an eyelid fold (epicanthus), and dense eyelashes created a natural barrier that better protected the eye from cold wind, snow dust, and bright dazzling light reflecting off the snow. Analogy with sunglasses: Imagine squinting in bright sunlight or in the wind. This adaptive feature works in a similar way, but is permanent. 2. Adaptation to strong ultraviolet radiation The high-altitude plateaus and steppes where these peoples lived are often characterized by high levels of UV radiation. A narrower and more protected eye socket helped reduce the harmful effects of radiation on the eyes. 3. Epicanthus (Mongoloid fold) This is a special skin fold at the inner corner of the eye that covers the lacrimal tubercle and creates the appearance of "narrow" eyes. It is the epicanthus that is the key anatomical feature that distinguishes the eye shape. Scientists believe that this fold developed as an additional protective mechanism against cold and dust. It is important to understand: This is not an absolute rule: Among the more than 1.4 billion Chinese, there is a great diversity of appearance. Many Chinese have large and round eyes, especially in the southern regions of the country. The term "narrow eyes" is a stereotype: Using such a description may be perceived as simplification and stereotyping, ... Read more