Late 19th century ophthalmoscopy tool. Ophthalmoscopic tools are used to examine the interior of the eye and measure its optical properties. This is a phoropter dating from 1880. Designed by the French ophthalmologist Emile Javal (1839-1907), this instrument is used to measure refraction within the eye and compare different lenses used during sight testing to determine a patient's optical prescription. This instrument was made by the French Roulot company.