The history of optic chiasm from antiquity to the twentieth century.

PURPOSE: The optic chiasm is an essential structure located at the skull base that stirred over time the curiosity of anatomists, who became more and more interested in its structure and function. Through centuries, the optic chiasm was viewed as a vessel crossing, a way of transporting tears secreted by the brain to the eye, integrating images, or responsible for coordinated eye movements. The paper aims to overview the history of understanding the optic chiasm from the beginnings of antiquity to the twentieth century. METHODS: We reviewed the literature and studied all the historical sources on optic chiasm and eyes in the works of ancient, medieval, Renaissance authors, and the seventeenth to nineteenth century works. RESULTS: The optic chiasm is a structure that fascinated ancient anatomists and made them develop various theories on its function. In terms of function, the optic chiasm had a history based more on speculation, the seventeenth century bringing its first understanding and reaching the peak in the nineteenth century with the understanding of the anatomical structure of the chiasm and its role in the visual process. CONCLUSION: The history of the optic chiasm is a fascinating time travel displaying the conceptual transformations that have been made in anatomy and medicine by our forerunners.