ARK 4000/ RK600 Auto Ref Keratometer: This is a precise and objective eyesight test device for ophthalmologists or optometrists, which is used to measure patient’s diopter, including sphere power, cylinder power, optical axis, pupil distance and corneal curvature, in order to provide reference data for eyeglass fitting, eye diseases diagnosis and treatment. This machine has unique optical system, accurate imaging analyzing and processing technology.