Amsler grid Amsler grid The Amsler grid, used since 1945, is a grid of horizontal and vertical lines used to monitor a person's central visual field. The grid was developed by Marc Amsler, a Swiss ophthalmologist. It is a diagnostic tool that aids in the detection of visual disturbances caused by changes in the retina, particularly the macula (e.g. macular degeneration, Epiretinal membrane), as well as the optic nerve and the visual pathway to the brain. In the test, the person looks with each eye separately at the small dot in the center of the grid. Patients with macular disease may see
The Canon of Medicine The Canon of Medicine The Canon of Medicine ( "al-Qānūn fī al-Ṭibb") is an encyclopedia of medicine in five books compiled by Persian physician-philosopher Avicenna (Ibn Sina) and completed in 1025. It presents an overview of the contemporary medical knowledge of the medieval Islamic world, which had been influenced by earlier traditions including Greco-Roman medicine (particularly Galen), Persian medicine, and Indian medicine. "The Canon of Medicine" remained a medical authority for centuries. It set the standards for medicine in Medieval Europe and the Islamic world and was used as a standard medical textbook through the 18th century in Europe. It