How do anophthalmia and microphthalmia affect eye development?

In the context of biology and malformation, anophthalmia and microphthalmia represent significant developmental anomalies of the eye. Anophthalmia is characterized by the complete absence of the eyes, while microphthalmia refers to the condition of having abnormally small eyes.1

These conditions are often the result of abnormal heredity and represent a failure or disturbance in the complex, interdependent process of eye development. Normal ocular formation relies on the precise interaction between the optic vesicle and the overlying epidermis to induce the formation of the lens and other structures. When these early developmental stages are disrupted—particularly during the period of blastogenesis, when the body plan is established—the resulting defects can be severe.213

While these conditions involve the absence or reduction of the eye itself, other related developmental failures, such as coloboma, involve the failure of ocular structures to fuse properly, leading to congenital fissures. These malformations highlight the vulnerability of the eye's highly integrated developmental pathway to genetic and environmental disturbances.413