Biology and pathology of the invertebrate eye.

Although this article is not a comprehensive review of ocular biology and disease across the millions of invertebrate species, it is hoped that it highlights the surprising gene homologies that influence ocular development despite the dramatic differences in resulting ocular development and final morphology. In the same way that ocular anatomy and physiology is undergirded by similarities in the genetic foundation of the eye, it is to be expected that eye disease in invertebrates, as it is studied in more depth, will show substantial homologies with the eye disease of the vertebrates that veterinary ophthalmologists are more used to treating.