Ibn Sina, known in the West by the name of Avicenna, was the most famous physician, philosopher, encyclopedist, mathematician and astronomer of his time. His major contribution to medical science was his famous book al-Qanun fi al-Tibb, known as the 'Canon' in the West. No deliberation on the science of medicine can be complete without a reference to Ibn Sina. Abu Ali al-Hussain Ibn Abdallah Ibn Sina was born in 981C.E. at Afshana near Bukhara (Central Asia). By the age of ten he had become well versed in the study of the Qur'an and basic sciences. He studied logic from Abu Abdallah Natili, a famous philosopher of the time and his study of philosophy included various Greek and Muslim books. In his youth he showed remarkable expertise in medicine and was well known in the region. At the age of seventeen, he was successful in curing Nooh Ibn Mansoor, the King of Bukhara, of an illness in which all the well-known physicians had given up hope. On his recovery, King Mansoor wished to reward him, but the young physician only desired permission to use his uniquely stocked library.

Ibn Sina traveled to Jurjan after his father's death where he met his famous contemporary Abu Raihan al-Biruni. Later he moved to Rayy and then to Hamadan, where he wrote his famous book Al-Qanun fi al-Tibb. Here, he treated Shams al-Daulah, the King of Hamadan, for severe colic. From Hamadan he moved to Isphahan (present Iran), where he completed many of his monumental writings. Nevertheless, he continued travelling and the excessive mental exertion as well as political turmoil spoilt his health. Finally, he returned to Hamadan where he died in 1037 C.E.

His major contribution to medical science was his famous book al-Qanun, known as the "Canon" in the West. The Qanun fi al-Tibb (the Canons of Medicine) is an immense encyclopedia of medicine extending over a million words. It reviewed the medical knowledge available from ancient and Muslim sources. Due to its systematic approach, formal perfection as well as its intrinsic value, the Qanun superceded Razi's (Rhazes') Hawi, Ali ibn Abbas's Maliki, and even the works of Galen, and remained supreme for six centuries. Ibn Sina not only synthesized the available knowledge, but he also made many original contributions. The Qanun (pronounced Qanoon) deals with general medicines, drugs (seven hundred sixty), diseases affecting all parts of the body from head to foot, specially pathology and pharmacopoia. It was recognized as the most authentic materia medica.

Among his original contributions are such advances as recognition of the contagious nature of phthisis and tuberculosis, distribution of diseases by water and soil, and interaction between psychology and health. He was the first to describe meningitis and made rich contributions to anatomy, gynecology and child health. Also, he was the first physician who suggested the treatment for lachrymal fistula and introduced medical probe for the channel.

Ibn Sina's Qanun contains many of his anatomical findings which are accepted even today. Ibn Sina was the first scientist to describe the minute and graphic description of different parts of the eye, such as conjuctive sclera, cornea, choroid, iris, retina, layer lens, aqueous humour, optic nerve and optic chiasma.

Ibn Sina condemned conjectures and presumptions in anatomy and called upon physicians and surgeons to base their knowledge on a close study of human body. He observed that Aorta at its origin contains three valves which open when the blood rushes into it from the heart during contraction and closes during relaxation of the heart so that the blood may not be poured back into the heart. He asserts that muscular movements are possible because of the nerves supplied to them, and the perception of pain in the muscles is also due to the nerves. Further, he observes that liver spleen and kidney do not contain any nerves but the nerves are embedded in the covering of these organs.

The Qanun (Canon) was translated into Latin by Gerard of Cremona in the twelfth century. It became the text book for medical education in the schools of Europe. The demand for it may be appreciated from the fact that in the last thirty years of the fifteenth century it was issued sixteen times - fifteen editions being in Latin and one in Hebrew, and that it was reissued more than twenty times during the sixteenth century. In 1930 Cameron Gruner partly translated this book into English entitled "A Treatise on the Canons of Medicine of Avicenna." From the twelfth to seventeenth centuries the Qanun served as the chief guide to medical science in the West. Dr. William Osler, author of the Evolution of Modern Science, writes: "The Qanun has remained a medical bible for a longer period than any other work."

Ibn Sina's Kitab al-Shifa (Book of Healing) was a philosophical encyclopedia, covering a vast area of knowledge from philosophy to science. His philosophy synthesizes Aristotelian tradition, Neoplatonic influences and Muslim theology. Kitab al-Shifa was known as 'Sanatio' in its Latin translation. Besides Shifa his well-known treatises in philosophy are al-Najat and Isharat. He classified the entire field into two major categories: the theoretical knowledge and the practical knowledge. The former included physics, mathematics and metaphysics, and the latter ethics, economics and politics.

Ibn Sina also contributed to mathematics, physics, music and other fields. He made several astronomical observations, and devised a device similar to the vernier, to increase the precision of instrumental readings. In Physics, he contributed to the study of different forms of energy, heat, light and mechanical, and such concepts as force, vacuum and infinity. He made the important observation that if the perception of light is due to the emission of some sort of particles by the luminous source, the speed of light must be finite. He propounded on an interconnection between time and motion, and also made investigations on specific gravity and used an air thermometer.

In the field of Chemistry, he did not believe in the possibility of chemical transmutation in metals. These views were radically opposed to those prevailing at his time. His treatise on minerals was one of the main sources of geology of Christian encyclopedist of the thirteenth century.

In the field of Music, his contribution was an improvement over Farabi's (al-Pharabius) work and was far ahead of knowledge prevailing elsewhere on the subject. Doubling with the fourth and fifth was a 'great' step toward the harmonic system. Ibn Sina observed that in the series of consonances represented by (n+1)/n, the ear is unable to distinguish them when n = 45.

Ibn Sina's portrait adorns the great hall of the Faculty of Medicine in the University of Paris.