Geographical reasons for the different eyes of Southeast Asians.

This is an adaptation to the extremely cold environment.

The former is unique to East Asians, while the latter includes most residents of Europe, America, Africa, Oceania and Southeast Asian islands, and is also the form of ancient human ancestors.

Why are the eyes of East Asians unique? The evolutionary explanation is that this unique eye shape is an adaptation to the extremely cold environment.

For example, there is a fat pad in the eye socket, the fat layer of the upper and lower eyelids is thick and the eye fissure is small.