Ophthalmology in Persian medicine.

Despite the fact that ophthalmology is one of the foremost branches of medicine, conceptualization of the structure and function of the eye barely advanced in ancient Western civilizations. At the early recovery of Persian civilization (9(th) century AD) after the extinction of the Sassanid Empire (7(th) century AD), translations of Greek medical textbooks played an important role in the development of medicine and the emergence of great Persian physicians such as Rhazes, Avicenna and others. Rhazes was a leading Persian physician whose medical teachings have as yet not been thoroughly explored. In addition to numerous books and articles in various fields, he authored a great medical Encyclopedia (al-Hawi al-Kabir) in 25 volumes. In this article, we are going to compare Rhazes' particular viewpoints about ophthalmology with those of other famous Persian physicians and some recent essays and textbooks. For this purpose we reviewed Rhazes' second volume of al-Hawi that is dedicated exclusively to ophthalmology and contains some major topics of ophthalmology including anatomy, physiology, pathology, diseases, disorders and treatments. Important themes were carefully extracted and compared with the tenets of modern ophthalmology. After collating Rhazes' viewpoints with the latest findings in this field, it was concluded that he had brilliantly written about the signs and symptoms, etiology and treatment of many eye disorders more than a thousand years ago. The amazing point is that there was no accurate equipment at the time to help him in his investigations. This study proved that Rhazes' theories conform to recent knowledge about ophthalmology in many aspects, and could therefore be the subject of further investigations.