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Eye Library / Diagnostic Tests / Phoropter (Refractor)

Photopter (refractor) is a device, placed in front of a patient's eyes, as they are asked to read an eye chart on the wall. The photopter contains various lenses that are changed by the examiner until the best corrected vision is determined. The eye chart on the wall used to be placed 20 feet in front of the patient, which meant the room had to be at least 20 feet long. Today, the distance has been modified by using mirrors to reflect the images, but they still appear to be 20 feet away.