Three typical pedigrees with hereditary glaucoma are presented, in which dominant goniodysgenesis is shown to be the actual genetic trait. Because of a marked variation in the expressivity of dysgenesis, the symptoms of the genetic malformation (elevated intraocular pressure and subsequent glaucoma) may appear early or late in life. Therefore, there is no justification in letting the patient's age at the onset of the symptoms decide the classification or the mode of inheritance of the glaucoma (infantile, juvenile, simple), when the common etiologic factor is a dominant dysgenic trait. Consequently, the term "congenital glaucoma" is inadequate and even misleading for glaucoma caused by an inborn malformation, but which may be manifested only after several years or even decades. Instead a new term "dysgenic glaucoma" is suggested as the logical term that also indicates the etiology.