I wish to present a conversion adapter which works well in converting the focal length of the light beam of the Poser slit lamp from 75 mm., which is brilliant for the cornea, to 100 mm., such as that provided by the older slit lamps, which allows much better study of the lens and the anterior vitreous. This small converter, which may be simply attached in front of the light beam of the Poser slit lamp, allows one to see the zones in the lens with quite as great clarity as that shown with the older textbooks—but not by the new Poser slit lamp, because of the shorter focal beam.
This instrument is available from the Parsons Optical Service in San Francisco. It is not useful for examination of the cornea; it increases the focal length of the light and is desirable chiefly for examination of the lens or the
JOHNSON LV. CONVERSION ADAPTER. AMA Arch Ophthalmol. 1951;45(2):195. doi:10.1001/archopht.1951.01700010200009