With the continent of Asia as large as it is, there exists a tremendous amount of diversity within numerous subregions. In current common medical usage with reference to eyelid surgery, the term "Asian" is usually meant to designate the regions of Eastern Asia (previously called "the Orient") and Southeast Asia (sometimes called the "Far East").
The term "Occidental" is generally used to mean "Western" or non-Asian. It is sometimes incorrectly confused with "Caucasian" (a non-preferred designation used to indicate a diverse grouping from Europe, North Africa, and parts of Asia).
People of Western Asian (often called the "Middle East") and Southern Asian (essentially, India) lineage show primarily Occidental anatomical traits, while those of Central Asia demonstrate a mixture of Occidental and classical Asian (sometimes called "Mongoloid") features.
Due to prehistoric migration, many people of native North and South American lineage possess distinctly "Asian" traits, including the heavier creaseless upper eyelid and inner epicanthal fold. Thus, even a patient from Argentina might be a suitable candidate for double-eyelid surgery.