A test that utilizes a machine called an autorefractor to provide a measurement of a person's refractive error. In other words, an automated version of a vision test. The patient looks into the autorefractor where they are shown an image, the most common being either a distant barn in a field or a distant hot air balloon at the end of a road, and the image is focused until the patient can see it clearly. The images take advantage of vanishing points to provide a sense of depth and appear circular due to the lens in the machine.
