Before revision: Technique The majority of autorefractors calculate the vision correction a patient needs (refraction) by using sensors that detect the reflections from a cone of infrared light.
After revision: optics inside a Shin Nippon Nvision K-5001 RefkeratometerTheTechnique The majority of autorefractors calculate the vision correction a patient needs (refraction) by using sensors that detect the reflections from a cone of infrared light.