||By the late 19th century the stage was set for the combination of mirror and speculum into one instrument.
The idea of using a perforated mirror set in a cylinder at an angle of 45' to the cylinder with an ear speculum at its end came to several aurists simultaneously, including Bonnafont and Brunton who had instruments manufactured in their name.
With these teaching mirrors were described that were worn in the centre of the forehead with double slots so that both eyes could be used, a system that can still be found today in certain electric headlights.
The focal length of the mirror for otoscopy was originally 5‑6 inches (13‑15 cm), much shorter than is presently used.
It was only after otology and laryngology became united that a universal mirror with a focal length of about 12‑13 inches (30‑33 cm) was adopted for use in both laryngoscopy and otoscopy.