Antique 1920's Woolf Phoropter Refractor Ophthalmic Eye Testing Device OpticianAntique 1920's Woolf Phoropter Refractor Ophthalmic Eye Testing Device Opticianantique Woolf Standard phoropter, a vintage ophthalmic instrument used in the early 20th century to determine eyeglass prescriptions. Function: It is a binocular refracting instrument containing various convex and concave lenses to measure refractive errors. Era: Devices like this were commonly used by optometrists and ophthalmologists during the 1920s and 1930s. Features: