SINCE Czermak, in 1858, developed the technique of indirect laryngoscopy and Kirsten, in 1894, the technique of direct laryngoscopy, the instruments for laryngoscopy have gone through a great evolution.1 The perfection of old instruments and the development of new ones has made direct laryngoscopy a more useful diagnostic and therapeutic tool; the development of modern anesthetic techniques now allows endoscopy to be done with more precision and convenience.
Magnification for endolaryngeal work was first used by Briinnings and Yankauer in the early years of this century. The method did not then become popular, probably because of difficulties with monocular vision and the discomfort of the patient. The operator was forced to choose a technique which would most quickly finish the procedure.
Due to the small inside diameter, most laryngoscopes allow only monocular vision. Yankauer designed a laryngoscope for binocular vision (Fig 1), but this did not have wide acceptance.
Jako GJ. Laryngoscope for Microscopic Observation, Surgery, and PhotographyThe Development of an Instrument. Arch Otolaryngol. 1970;91(2):196–199. doi:10.1001/archotol.1970.00770040266019