Aniridia, anophthalmia and microphthalmia have been associated with haploinsufficiency of SOX2 while anterior eye defects, including defects of the iris and ciliary body have been associated with haploinsufficiency of PAX6 in humans [34], [37], [42], [43], [44], [45], [46], [47]. This evidence concerns the gene PAX6 and microphthalmia.