FROM OPHTHALMOLOGY TO OPTICAL SCIENCE: A COMPARATIVE STUDY OF ALI IBN ISA AL-KAHHAL AND IBN AL-HAYTHAM

Abstract

The Islamic Golden Age witnessed remarkable advancements in optics, with scholars such as Ali ibn Isa al-Kahhal and Ibn al-Haytham making significant yet distinct contributions. Ali ibn Isa, a leading ophthalmologist, compiled Tadhkirat al-Kahhalin, a comprehensive medical treatise detailing over 130 eye diseases, diagnostic methods, and surgical procedures, particularly in cataract treatment (Abudawood et al., 2021). His work was instrumental in shaping medieval and early modern ophthalmology (Library of Congress, 2021; Henry & Jaffe, 2020).

In contrast, Ibn al-Haytham, often regarded as the father of modern optics, transformed the field with his empirical and mathematical approach in Kitab al-Manazir (Masoud & Masoud, 2006). He challenged the Greek emission theory of vision, instead proposing the intromission theory, supported by experiments on light refraction, reflection, and perception, as well as his pioneering study of the camera obscura (Raynaud, 2022; Sabra, 2024; Wilk, 2015).

Despite their different approaches—Ali ibn Isa’s being medical and descriptive, and Ibn al-Haytham’s being theoretical and experimental—their work collectively advanced the understanding of vision. Ali ibn Isa’s clinical expertise complemented Ibn al-Haytham’s optical theories, influencing later scholars such as Roger Bacon and Al-Farisi, who bridged the fields of medical ophthalmology and optical physics. This paper critically analyzes their methodologies, comparing their strengths and limitations while assessing their broader influence on both medieval and modern science. The review concludes that their combined legacy laid a foundation for future developments in optics, demonstrating the interconnectedness of medical practice and scientific inquiry.