In the truth the eyes of the orientals (and not exclusively of the Japanese, as well as of Chinese, native of Koreas, tailandeses, etc) “are not pulled” and yes the eyelid is smoother, and not curve as in the occidental eyes. The ridge palpebral superior, generally clear-cut and about7 mm above of the ciliar line in the occidental people, is absent in the orientals. This ridge becomes more evident if opening the eyes. It has in the orientals the aspect amendoado with rise of it I sing lateral. The inferior eyelid is characterized by excess of orbital fat, fat daily pay-tarsal (posterior portion) and excess of skin in the medial part.
These characteristics had probably elapsed of a process of natural election, since the eastern eyes more are adjusted for protection against the rigorous cold. Possibly the populations that had obtained to fix residence to the east of the first Himalaia had fort trend in this profile, and that it was remained with passing of the centuries.
Moreover, this trace must have been an advantage for the inhabitants of cold regions, therefore its function is seemed the one of the eyeglasses of the esquiadores, that possess a viewfinder in crack form to reduce the luminosity reflected for the snow. This seems logical, since mongolóides, that they have this characteristic, had appeared of an area frozen in the north of Asia, has about 10 a thousand years. As the white imensidão of the cold regions it very reflects the light solar that arrives at the surface, who deferred payment in these places can have sight problem in the long run - since momentânea blindness until certain upheavals of retina -, what it would explain the predominance of the eyes pulled in the natural election.
It has differences between the different standards (Chinese, korean, Japanese) but that they are subtle for the occidental eyes.