Nomenclature of iris color]
[Article in German]
Heterochromia simplex (Streiff) or true heterochromia of the iris (H. vera, H. congenita) is the product of mosaic inheritance arising from variable expressivity of the parental characteristics. This is different from the "mixed iris", which shows a mixture of colours, in which the components are no longer distinguishable but form a new shade.
PMID: 6660839 [PubMed - indexed for MEDLINE]