In eye genetic disorders (Microphtalmia/Anophtalmia/ Coloboma-Optic Nerve Hypoplasia, MAC-ONH), only between 40 and 50% of cases are explained by mutations within the exomes of several genes, including SOX2, OTX2 and PAX6 among the most frequently mutated [50]. The gene discussed is OTX2; the disease is coloboma.