Scientific Instruments > Scientific Optical

Optometer, an Early French Instrument for Testing Visual Acuity

Item#: SOI402

Price: $500.00

 

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Optometer, an Early French Instrument for Testing Visual Acuity - click to enlarge.

This is a single lens optometer instrument. The lens and brass disk are aligned on an ebony bar which has numbers inscribed into it: 1-16 and then: 18, 20, 24, 30, 36, 42. There is a small space then 16-2 in jumps of 2. The lens is fixed inside a wooden funnel which is held in place on the bar by a pin in the ebonized handle. The brass disk can slide along the bar for focusing with the aid of an ebonized handle. Overall length 25 cm (9.8 inches). Accommodation and visual acuity represent the ability of the eye to distinguish objects at different distances and its flexibility in the transition from near to far or far to near.