Ophthalmoscope, Paris, France, 1845-1865
Herman von Helmholtz (1821-1894) invented the ophthalmoscope in 1851. It became the key instrument for viewing the retina and other internal structures of the eye. This simple steel ophthalmoscope is a very early example. It was made by German instrument maker Hermann Wülfing Lüer, in Paris. Early ophthalmoscopes used reflected sunlight from mirrors to view the inner eye. Modern examples use a built-in light source such as a halogen bulb. They assess the inner eye and help diagnose complaints such as glaucoma. Glaucoma is increased pressure within the eyeball, leading to loss of sight.