AO Trial Lens Set - Charles Prentice and AO
Recently discovered in the collection of the Optical Heritage
Museum is a AO Trial Set
that was presented to Charles F. Prentice, who designed the early trial sets made by AO.
Learn more about AO and Charles Prentice on this page.
Inscription on the Trial Lens Set given by AO to Charles Prentice :
Charles F. Prentice, M.E.
With the compliments of the
American Optical Company,
In Recognition of his services to the company as an Opticist
Southbridge, MA USA
Now in the Optical Heritage
AO Gift to Charles Prentice (after 1900)
C. F. P.— Charles F. Prentice, M. E., New York City, N. Y.
President, New York State Board of Examiners in Optometry; Special
on Theoretic Optometry, Columbia University, New York. Author of A Treatise
on Ophthalmic Lenses (1886) ; Dioptric Formulas for Combined Cylindrical
Lenses (1888); A Metric System of Numbering and Measuring Prisms (the
Prism-dioptry) (1890) ; The Iris as Diaphragm and Photostat (1895), and
other optical papers.
Oxford University Press info on Charles Prentice
Charles Prentice and
1900 - AO introduced the first Trial Lens sets
AO produced a trial lens set design by Charles
Prentice. This set was composed of biconcave minus lenses of true curve
out the convex plus lenses were designed to neutralize the minus lenses.
This meant that the lenses were almost exactly true vertex refractions or effective power. The first lenses so made.
This principle is still used in our trial lens sets. Only the rings & cases have been updated.
Read Charles Prentices Article from the below Journal from 18-Jan-10
Another article from the above is AO's
George Wells's recollection of his early days making Spectacle Frames
It is a fascinating glimpse into how the industry was born!
1982 Don Whitney Paper on Prentices Rule:
Rule - Its Application and Limitiations (with some thoughts about Plano
Lenses) - 2/12/82 Appendix
Diagram - 30-Apr-06
Don Whitney Ophthalmic Optics Technical Paper
The AO Lensometer
Note "Lensometer" was an AO Trademark name
More about AO Scientific Instruments achievments/timeline
to AO History Main Page