An epicanthal fold, epicanthic fold, or epicanthus is a skin fold of the upper eyelid (from the nose to the inner side of the eyebrow) covering the inner corner (medial canthus) of the human eye. The epicanthal fold is present in people of East Asian and Southeast Asian descent, as well as other ethnic groups including some Native Americans and Africans. Epicanthal folds may also be seen in young children of any race before the bridge of the nose begins to elevate.
The term "epicanthal fold" refers to a visually categorized feature; however the underlying physiological reason and purpose for its presence in any given individual may be entirely different.
All humans initially develop epicanthal folds in the womb. Some children lose them by birth, but epicanthal folds may also be seen in young children of any ethnicity before the bridge of the nose begins to elevate. They may persist where birth is pre-term, and sometimes also where the mother is alcoholic.
Epicanthal folds can cause a child's eyes to appear crossed, a scenario known as pseudostrabismus.
In many caucasian backgrounds and other groups who don't commonly possess the trait, the presence of the epicanthal fold can be a symptom of fetal alcohol syndrome, chromosomal disorders such as Down syndrome, Cri du Chat syndrome, or pre-term birth.