Non-direct vision surgical microscope is an optical microscope, specially designed for surgical environment, and usually used for microscopic examination. The design feature of the surgical microscope is that the magnification is usually 4x-40x, which is convenient for disinfection or disinfection of components and ensures cross-infection control. There is usually a prism to separate the light beams, so that the assistant can also visualize the surgical procedure or allow taking photos or videos at the surgical site. The medical fields where surgical microscopes are widely used include plastic surgery, dentistry (especially endodontics), otolaryngology, ophthalmology and neurosurgery.