Iridogoniodysgenesis type 1 is a rare condition that affects the eyes. People with this condition are born with malformations of the iris (the colored part of the eye) and cornea, which eventually lead to early-onset glaucoma. The irides of affected people are unusually dark. For example, studies of the condition often describe 'brown' irides as a dark, chocolate color and 'blue' irides as a very dark, slate gray. The iris also lacks the usual pattern and has a smooth appearance. Iridogoniodysgenesis type 1 is caused by changes (mutations) in the FOXC1 gene and is inherited in an autosomal dominant manner. Management is based on the signs and symptoms present in each person and is generally focused on the screening and eventual treatment of glaucoma.