General Information

Serial #

888

Part Number

1

Total Parts

1

AKA

keratometer

Patents

N/A

General Description

Predominantly black metal instrument [includes brass and cast metals]; red rubber [?] fittings atop illuminated boxes mounted on disk; off-white fabric covering on electrical cord; brass telescope fitted with clear glass optics; white synthetic panels fitted in front of light boxes; glass bulbs; off-white markings on adjustment scales; bakelite [?] power switch and housing

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

54.0 cm

Width

40.0 cm

Height

59.2 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Medical Technology

Category

Medical equipment

Sub-Category

N/A

Manufacturer

AKA

Meyrowitz

Country

United States of America

State/Province

New York

City

New York

Context

Country

Unknown

State/Province

Unknown

Period

Presumably used c. 1900 +

Canada

Part of a large collection of medical artifacts, archival material & trade literature transferred to CSTM in 2002 from the former History of Medicine Museum, Toronto, ON.

Function

Used to measure the curvature of the anterior surface of the cornea.

Technical

The ophthalmometer was invented c. 1855 by Helmholtz [who had invented the ophthalmoscope 4 years earlier]. Although it was accurate, the need for 15-20 readings per patient plus calculations prevented its adoption until the late 1880s, when it was simplified. In 1894 the American Medical Association [AMA] advocated that the ophthalmometer, ophthalmoscope, etc. be used for objective eye examinations. (Reiser, p. 49) Ophthalmometers measure the radius of the curvature of the anterior (front) surface of the eye. They facilitate the measurement of the diameter of the cornea, allowing the user to judge the volume of the eyeball. They were used when prescribing and fitting spectacles, as the lens vertex and corneal vertex must be considered. In modern times, they have been used mainly for fitting contact lenses. The Javal and Schiotz design (1881) of the instrument was one of the first successful and widely adopted models.

Area Notes

Unknown

Details

Markings

"JAVAL-SCHIOTZ/ OPHTHALMOMETER/ [logo]/ 888/ PATENTED APR. 24, 1900./ E.B. Meyrowitz/ NEW YORK PARIS" cast in raised print on plate at base of telescope mounting. Scales 0-165 [double]divided at intervals of 5 and labelled in increments of 15, and 5-45 over 5-13 divided in single increments. UHN catalogue no. "986.18.4" printed by hand in white ink on instrument. [NB: arc on which illuminated boxes can be positioned is divided: markings are present but worn/illegible at time of cataloguing.]

Missing

Unknown- appears complete. Chin and forehead rest may originally have been leather-covered.

Finish

Predominantly black metal instrument [includes brass and cast metals]; red rubber [?] fittings atop illuminated boxes mounted on disk; off-white fabric covering on electrical cord; brass telescope fitted with clear glass optics; white synthetic panels fitted in front of light boxes; glass bulbs; off-white markings on adjustment scales; bakelite [?] power switch and housing

Decoration

N/A