Since the discovery of the Sterner principle in 1619, it has been applied to many automatic optometers to this day. After 1759, a subjective optometry machine emerged, and it was not until the 20th century that objective automatic optometry machines were introduced. But this type of refractometer needs to adjust the target projection area correctly, and cannot be completely relaxed and adjusted. The inspection results are not accurate enough, so it has not been widely promoted.

With the development of electronic computers, there have also been new developments in objective optometry. Since 1969, automatic optometers have used infrared light as the light source and electronic automation systems to adjust the visual standards. The accuracy can reach 0.12-0.25D, and the mechanical device is flexible and exquisite, with multiple functions. It is equipped with various visual acuity charts and adjustment devices, and has the function of measuring deviation and stereo vision.
In recent years, the functions of new refractometers have become increasingly perfect. They not only have subjective examination functions, but also can check and adjust functions, with accurate results. They are a new type of subjective binocular refractive analyzer. Various types of automatic refractors have emerged, including subjective and objective types. The most advanced one is the use of infrared light sources and electronic computer devices in conjunction with automatic refractors, also known as computer refractors. The operation method is simple, and the optometry results printed on recording paper can be obtained in seconds. However, the equipment cost is relatively expensive, and patient cooperation is not good, which can easily lead to error