Haussler’s Pupilometer — Antique PD Instrument c.1900
Haussler’s pupilometer is a rare antique interpupillary distance instrument dating from around 1900. This example survives in fine condition and includes its original illustrated instruction card — headed “Haussler’s Pupilometer: The Accurate P.D. Measure for Refractive Results.” That card alone adds wonderful period charm and documentary authenticity to the piece. When Haussler first released this instrument it carried a retail price of $3.00 — a significant sum at the turn of the century.
Why Interpupillary Distance Measurement Matters
Interpupillary distance — or P.D. — measures the gap between the centers of both pupils. Opticians need this measurement to position lenses correctly in front of each eye. Without an accurate P.D., lenses cause eyestrain, headaches, and blurred vision. Getting it right has always been fundamental to good optical dispensing and comfortable vision for patients.
How Haussler’s Pupilometer Works
Haussler’s pupilometer features crosshairs centered carefully over each of the subject’s pupils. The examiner reads the interpupillary distance directly from the top scale on the device. This straightforward design delivered reliable, repeatable results. Optical dispensers trusted it to give the clearest, most comfortable vision possible for their patients. Browse the full antique eye exam equipment collection to see more early optometry instruments of this caliber.
Rarity and Collectibility
Very few examples of Haussler’s pupilometer survive today with their original instruction cards intact. That price of $3.00 reflected the precision engineering required to produce such a finely calibrated tool. For broader historical context, the Museum of Vision documents how measurement tools like this shaped modern eye care.
Condition and Provenance
The instrument itself is clean and intact. The crosshair mechanism functions as intended. The original instruction card is present and legible. Together they form a cohesive, displayable unit of genuine optometric history.
