Epicanthic fold Epicanthic fold The epicanthic fold is the skin fold of the upper eyelid, covering the inner corner (medial canthus) of the eye. Various factors influence whether epicanthic folds form, including ancestry, age, and certain medical conditions. The highest frequency of occurrence of epicanthic folds are found in: East Asians, Southeast Asians, Central Asians, North Asians, some South Asians, Polynesians, Micronesians, Indigenous Americans (as well as Mestizos), the Khoisan, Malagasy. In some of these populations the trait is almost universal. Epicanthic folds occur, but at considerably lower frequency, in: Europeans (e.g., Scandinavians, English, Irish, Hungarians, Russians, Poles, Lithuanians, Finns, Estonians and
Epicanthic fold cold climates. It has also been postulated that the fold itself might provide a level of protection from snow blindness. Though its appearance in peoples of Southeast Asia can be linked to possible descent from cold-adapted ancestors, its occurrence in various African peoples precludes a cold-adaptive explanation for it appearing in the latter groups. The epicanthic fold found in some African people has been tentatively linked to protection for the eye from the high levels of ultra-violet light found in desert and semi-desert areas. Many fetuses lose their epicanthic folds after three to six months of gestation. Epicanthic folds may