One of the reasons I like the Stereo Microscope over the Loupes is the stand alone microscope can be focused and from there, it doesn’t matter how your head moves, you have the treatment area in focus. With loupes, your head has to be held in place even as you work. Yawn and you are back at zero. If either you or your victim, er patient are fidgety, you will get a headach just from all the times your eyes are out of focus.