Catalogue Number: 2011
Year Of Publication/Manufacture: c1936
Time Period: 1900 to 1939
Place Of Publication/Manufacture: USA
Publisher/Manufacturer: American Optical Company
Description Of Item: Black metal & glass ophthalmoscope with internal illumination and connection for power supply lead. Engraved:'No 144P GIANTSCOPE/ AMERICAN OPTICAL CO/ U.S.A.' Rear marked:'US PATENT No/ 1,918,848/ 1,951,664/ 1,956,867/ 2,078,254/ PAT. PEND./ MADE IN/ U.S.A.' Three coloured filters to rear of instrument; green, blue, amber. Wheel of lenses +7 to -8 in 1D steps. Supplementary lenses:+16. +8, plano, -16, -22 D. The instrument features a polarizing filter to lessen corneal reflections, to which the patent numbers refer. It has a black leatherette covered case with burgundy velvet lining, hinged lid and 2 slide button catches .Case Dimensions: L:24.5cm x D:11.3cm x H:5.0cm. Instrument: 225 x 42 x 25 mm.
Historical Significance: The Giantscope was first produced in 1926. It was one of the first ophthalmoscopes to use a polarizing filter to lessen corneal reflections. The first three patents were granted in 1933 & 1934. The fourth was not granted until April 27, 1937. All were for Edwin H Land's inventions for polarizing filters.
How Acquired: Not known
Condition: Very good
Location: Archive Office. Cabinet One Drawer 12