[Maurice Sourdille and the operating microscope]

The authorship of the operating microscope appears to be shared by Nylén, who had the idea of using a microscope for ear surgery and Gullstrand, who invented the slit-lamp and who was probably the counsellor of Hölmgren in his work on operative field magnification. Hölmgren was the first to use an operating binocular magnifying glass and Sourdille created the first binocular magnifying glass designed for microsurgery.