Originally Posted by kwolicki
as a practicing Otolaryngologist x 30 yrs, I think I can speak with some authority.
Make no mistake, the concentric view through the head mirror allows naked eye visualization down very small holes (i.e. the nose, ear) and when accessible by mirror examination, the view is superior to even a flexible laryngoscope. The downside is the need to have a non-moving subject and the correct geometry with a light source and your mirror. For children, or maybe hospital consultations, a single light source headlight, as those pictured above, will be adequate for many purposes. In my office, we're about half and half headlights vs head mirrors. I can tell you, though, that I see things deep in the nose with my head mirror exam that my partners cannot see with a headlight and must resort to an endoscope (there is always a parallax error between your line of sight and the position of the light source, no matter how tightly collimated.)
The one exception is the Lempert headlight which I find indispensible in the operating room, doing minor nasal procedures in my office, and as a mobile light source when in the hospital. Again, the slotted mirror with the light bulb directly between the eyes reduces parallax error well. The design is old, but never yet surpassed. I understand they are going out of production (Karl Storz) but no one has yet shown me an acceptable replacement that is as functional. The Lempert would be rather ungainly going from room to room seeing patients, and to my knowledge, there is no battery powered version available. People have proposed the Welch Allen which has adjustable interocular distance, magnification, and a central light source (it is basically like two small periscopes, one for each eye, to bring the optical axes closer together) The concept is good, but I find actually using one, especially with bi-focal glasses, just about impossible.
Good luck- whatever you choose you'll be using a lot, and depending on it for the accuracy of your examinations.