One way to do microsurgery is to use jeweler’s loupes and a headlight as shown above. If more than 2X or 3X magnification is needed, the surgeon must hold very still to stay in focus. Another difficulty is that the light and the glasses are not quite in the same plane, so in a deep operative field, some of the light gets blocked when eyes are on target.
A better solution for spine surgery is the operative microscope, demonstrated below on the left. It provides stable focus at higher magnifications due to Its platform and better visibility due to its built-in coaxial lighting. Below right shows the ‘scope being used in a lumbar microdiscectomy. It’s covered with a sterile plastic drape so the surgeon can move it in all directions and change magnification with his hands. A foot pedal is used to re-focus when needed.