AO Scientific Instruments History
The AO Lensometer
Note "Lensometer" was an AO Trademark name
AO Promotional photo (~1920) for the first marketed AO Lensometer which
was first sold in 1921;
the principal by which we still measure lenses today. In 1916, AO began
using the Lensometer in its factory/ branches.
In
1917, it line of Centex lenses was introduced
which were designed by effective power (now the Industry Standard).
This website page shows the lineage of the AO Lensometer over time,
an instrument which
is still one of the most important devices in the Ophtlamic Industry
today.
Dr.
Tillyer in the image above from a 1918 Booklet on the Lensometer
Download this first booklet (4mb pdf)
Download
the AO 1938 Booklet about this model, and the complete background
of
the AO Lensometer up until then.
It was written by Dr. Estelle Glancy
1914 AO Lensometer which predated the first device sold in 1921
Early Lensometer (Serial #002) - 1921
AO Optical Heritage Museum Collection
AO "Wellsworth"
Lensometer
ad from Febrary, 1922 showing Doc
Tillyer measuring a lens
A look at the early development/ timeline of AO's Lensometer (Left image
below)
Model 603 from 1938 - The Junior AO Lensometer (at right
above)
Information on WWII and AO Lensometers used in the war (bottom link)
AO Lensometer Catalogues from 1947 (L)- list price $310 and 1958 (R)- list price $435
1952
Instructions / Manual & Maintenance Booklet
Download pdf (10mb)
New July 7,
2009
1956
AO Electronic Focusing Lensometer by Whitney/Haynes/Gunter New
Aug 3, 2009
AO Lensometer Catalogue - 1959 (above)
A simple diagram of the principal used in the AO Lensometer to measure
tranmission dioptric power of a spectacle lens.
This is from Don
Whitney's 1981 Optics training slides that he compiled for a course
given at that time.
1977 Brochures of two popular AO Lensometers
Download AO 12603 Lensometer Brochure
Download AO 12620 Lensometer Brochure
AO Lensometer Blueprint - 1971
Specialize AO Lensometers
The one shown below was used to develop the AO Tillyer Masterpiece
lens series; Ina Pasay Dawson is shown here using this device in the 1970's.
This device was built a couple 1-2 decades before. It permitted one to
measure off-axis tranmission power of the lens, to determine the optical
errors the eye would see as the eye rotates away from optical center.
This device is in the Optical
Heritage Museum collection, along with all the models shown above.
The device below (1977) used a modified in AO 12603 Lensometer to accomplish the same thing as the "Masterpiece Lensometer" above. It permitted one to rotate a lens (using set center of rotation distances) to similuate the eye motion away from optical center. With this rotation, power errors and prism retulted. To measure these errors, the telescope was rotated as shown to determine whether the design / fabrication met AO and Industry Standards at that time. ANSI Z80.1 -1972 required lenses to meet specific off-axis tolerances for power errors.
AO Lensometer Calibration Lenses
This is the AO primary true-power lens set Calibrated by Doc Tillyer
when he worked at the National Bureau of Standards prior to joining AO.
Each lens was measured for its refractive index (a sliver taken from
the edge). The curves were measured and then the resulting power calculate.
Two lenses were recertified in 1977 and had not changed. It is this
set by which all AO Lensometers were originally calibrated.
The set (and another secondary set) is part of the Optical
Heritage Museum collection.
Blair Wong (Ben Franklin Institute of
Technology - Opticianry Dept Chair & Exec Director of MA
Opticians Assocation
and Diane Matuck (Board of MA Opticians Assocation) examine the AO
NBS set from 1916.
1977 AO Lensometer calibration lens set ad above and two below today.
This AO Lensometer was modified ~ 1987 and used to check the reflected
image of Progressive Lens mold engravings;
it was not used for Transmission measurements, but was a clever and
accurate way to examine engraving quality.
May
2009 Lensometer Display (courtesy of the Optical Heritage Museum)
at the Southbridge Hotel and Conference Center
