History Of Phoropters


I don’t know who invented the Phoropter and can’t seem to find information on who invented it. What we do have is some early shots of Phoropters and resources on where to purchase vintage optical and medical equipment .

A phoropter is an instrument commonly used by eye care professionals during an eye examination, containing different lenses used for refraction of the eye during sight testing, to measure an individual’s refractive error and determine his or her eyeglass prescription.[1]

Circa 1865 Photo:theburnsarchive.blogspot.com

Typically, the patient sits behind the phoropter, and looks through it at an eye chart placed at optical infinity (20 feet or 6 metres), then at near (16 inches or 40 centimetres) for individuals needing reading glasses. The eye care professional then changes lenses and other settings, while asking the patient for subjective feedback on which settings gave the best vision. Sometimes a retinoscope or an automated refractor is used to provide initial settings for the phoropter.

Circa 1930 Photo: www.optik-museum.de

Phoroptor is a registered trademark name currently owned by Reichert Technologies, filed Apr 25, 1921 with the USPTO, serial number 71146698. The common name is refractor. The current version is named “Ultramatic RX Master Phoroptor”. (Wikipedia)

From Industrial Anatomy: An interesting collection of 3 Phoropters hat are all mounted on desk stands. It’s just a hint as to the variety you will find when collecting antique medical devices. They have at least 6 different examples in stock. Prices range from $375 to $500. They can be purchased at Industrial Anatomy 


You Can find Current and New Phoropters At:


Sources And Where to Find Vintage Optical Equipment


Kala Mid Page


  1. Edgar Tillyer of American Optical was granted a patent for the Phoropter in 1923. The name was derived from the fact that a phoropter combined a “phorometer,” an earlier instrument for measuring phorias, with a rotating disc of lenses for measuring refractive error. Bausch & Lomb later introduced their own version, called the Refractor.

  2. Thanks to Darryl Meister for the factual background on the American Optical “Phoroptor”. AO and B&L (Greens Refractor) shared the market until the early 70s when AO introduced the Ultramatic Rx Master Phoroptor with synchronized cross cylinders. This improvement gave AO (now Reichert Technologies) a commanding market lead. With the sychronized cross cyl patent now expired, the Reichert Phoroptor is probably the most copied ophthalmic instrument on the market.

    Patrick Dundas

  3. Darryl you are mistaken. The term phoroptor was coined in 1921 by Henry Dezeng of Dezeng Standard Co. of Camden, New Jersey. He only changed the design slightly from an earlier instrument of his, starting in 1917 DeZeng was making one called a phoro-optometer, but he was not the first, by a long shot. In 1925, AO bought DeZeng and the patent, as well as the trademark “phoroptor”, turned it upside down, and sold it as the DeZeng phoroptor by American Optical, and then Edgar Tillyer chaged it slightly and made some improvements, and got another patent in 1932. They dropped the Dezeng name after that. In 1931 B&L introdeuced the Greens Refractor which is why AO had to improve theirs, the DeZeng was a piece of rubbish compared to the B&L.

  4. I can identify all the phoroptors in the pics on this page. “F” is the 1932 AO version of the phoroptor. It will have about 6 patent dates on it, the latest being 1932 and the earliest being 1917. “E” is a DeZeng phoroptor, I believe it’s from around 1922. “C” and “D” are a couple of Genothalmic Refractors, they were made by General Optical of Mount Vernon, NY, patent date 1917. These are upside down to go on the stand, mine is rightside up like a modern phoroptor, otherwise they are identical. “A” and “B” are not phoroptors, they are phorometer trial frames. I can’t tell from the pics but they are probably DeZeng. They have no battery of rotating lenses (optometer) so you have to insert trial lenses in the frame. One of the first instruments which we would call a phoroptor by modern standards is the Woolf Ski-Optometer made in 1910. It looks like a phoroptor but it’s really small. And it’s upside down to go on a stand. I have one in really nice condition. It’s called a ski-optometer because you did skioscopy with it. Before then, there were “compound optometers” going back to 1885, there was one called the Berteling Optometer and a few others.

  5. Hi there,

    I would please like to know if someone can help me identify what phoropter I have. All that is written on it is that it is a TOC and that it is made in Japan and the model no. Any help would be appreciated.

    De Villiers

  6. I would like to correct my post from November 9, I made a few mistakes.

    1. “E” is an AO DeZeng, meaning it was made after 1925 when AO bought DeZeng. It’s not 1922 like I said.

    2. The Woolf Ski-Optometers were not made in 1910, they have patent dates of 1910 and 1917. The 1910 patent looks nothing like the actual manufactured device, which looks more like the 1917 patent. They were all made from around 1917 to 1920 when Woolf sold out.

    3. In 1920 General Optical bought Woolf and the patents from Woolf, and used the 1917 patent date for their Genothalmic Refractors. These were manufactured from 1920 until the late 1930’s.

    4. There were many compound optometers before 1885, Bertelling was not the first.

  7. I am the grandson of Michael Woolf the inventor of the Woolf Ski-Optometer. I would like to know more about the company in which my forebearers were involved. If you have any more information about my family please contact me.
    My phone # is 760-602-0929.
    My uncle Daniel Woolf and my father Emanuel Woolf were heavily involved with the manufacturing company.

    Thanks for your interest in this early phoropter.

    Milton Woolf

  8. Interesting:

    I contacted Cathy and thanks her for posting the info. I have a Johnston Optical “Eye Globe”
    that predates all the “eye measurement instruments” mentioned. Optometers were made by Hardy as well as several others. I would suggest those interested research names such as
    Meyerowirz (General Optical) and Brown , Spencer Optical to further discuss the evolution.

  9. Milton I have a Woolf ski-optometer. I wish I knew more about it, but what I know is they were made from 1917 to around 1924 when the company was sold to General Optical who started making the Genothalmic Refractor. The book about the Woolf Ski-optometer was written by Daniel Woolf in 1921. Was he a son of Michael? (So your father is Daniel’s brother??). Is there anybody in your family who knows more??

  10. I would like to correct my correction of the posts describing the pic. E and F in the pic are actually the same AO phoroptor model, number 589, which came out in 1934. They are not the 588 which came out right after AO bought Dezeng in 1925.

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