Muller's mirror

**Müller speculum** is an instrument used in ophthalmology to dilate the pupil of the eye through intracavernal injection. This mirror is the main tool for successful cycloplegia, which allows you to diagnose a number of pathologies of the retina and optic nerve. Also, the Muller mirror is widely used in the practice of traumatology, oncology and other areas of medicine.

The Müller speculum was invented by German ophthalmologist Joseph Müller in 1868 during a scientific expedition to Peru. His scientific discovery was not widely known and applied immediately because he was a young doctor when he conducted the research, but today we can safely say that this development was one of the most important and successful inventions in the field of ophthalmology. The mirror consists of two flat and opposing plates, with a cutting edge on top, and has a hole in the center with a triangular or semicircular shape. The use of a mirror occurs in two stages: first, the doctor makes a hole in the apple (white) of the eye through the conjunctiva, then he inserts the mirror into the resulting hole and, squeezing two plates with his hands, rotates it counterclockwise along the axis by 20-30 degrees. The entire mirror moves along the convex surface of the apple parallel to the fundus of the eye. As a result of this maneuver, the upper surface of the apple breaks through, creating a cavity from the sclera and the bone layer of the skull. If the operation is performed correctly, the bubble of the intrasclar substance ruptures and its contents flow down. In this case, pupil dilation is caused by both reflex and direct changes in the pupil area.