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 :

Presented to
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 Museum collection-
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 Lecturer
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  Optometry
 

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:

Prentice's Rule - Its Application and Limitiations (with some thoughts about Plano Lenses) - 2/12/82   Appendix Diagram - 30-Apr-06
Other papers:
Don Whitney Ophthalmic Optics Technical Paper

Learn about:
The AO Lensometer
Note "Lensometer" was an AO Trademark name