<unk>  A doctor using a<unk>  to illuminate his patient's nasal passages. A<unk>  is a simple diagnostic device, stereotypically worn by physicians, but less so in recent decades as they have become somewhat obsolete. A<unk>  is mostly used for examination of the ear, nose & throat. It comprises a circular concave<unk> , with a small hole in the middle, and is attached to a<unk>  band. The<unk>  is worn over the physician's eye of choice, with the concave<unk>  surface facing outwards and the hole directly over the physician's eye, providing illumination like a ring light. In use, the patient sits and faces the physician. A bright lamp is positioned adjacent to the patient's<unk> , pointing toward the physician's face and hence towards the<unk> . The light from the lamp reflects off the<unk> , along the line of sight of the user, with the light being somewhat concentrated by the curvature of the<unk> . When used properly, the<unk>  thus provides excellent shadow-free illumination. Because they were once in common use, notably by general practitioners and otorhinolaryngologists,<unk> s are often a stereotypical part of a physician's uniform by costumers and prop men e.g. in comic routines. The main drawback to<unk> s was that they required some skill to use well. They are rarely seen outside of the ENT setting, having been largely replaced by pen lights among general practitioners. They are still used by some otolaryngologists, particularly for examinations and procedures involving the oral cavity, although many are switching to fiber optic<unk>  lights.
Head mirror
Eye chart
Audio power amplifier
Lensmeter
Schimmelbusch mask
Focometer
Pupilometer
Tele-audiology