PAX6 and aniridia: Haploinsufficiency of PAX6 leads to aniridia in humans, a rare eye disorder named for underdevelopment of the iris.1, 2 However, there is a spectrum of ocular symptoms associated with aniridia, and most major eye structures are impacted.1, 2 Patients are born with low vision primarily due to hypomorphic fovea but will frequently experience a progressive loss of vision due to cataracts, corneal clouding, and glaucoma.1