Optometer M. Perrin & Mascart, C 1880
A fine example of an Optometer by Maurice Perrin and Mascartâ€™s, P. Roulot Opticien Paris. first introduced C1875. Â Perrin & Mascartâ€™s optometer is among the most technically advanced of the 19th century. In good condition with virtually all of its original lacquer intact.
The optometer consist of double refraction lens of calcspar, give double readings and a greater precicion in determining the distance of signs.