The ARK-700A is an auto ref/keratometer with Auto-Tracking contains both a refractometer and a keratometer in one unit. The refractometer objectively measures the refractive errors of sphere, cylinder, and axis for the lens that corrects the patient’s vision into emmetropia. The keratometer measures the corneal curvature radius, corneal refractive power, corneal cylindrical power, and corneal cylinder axis. This device has a main body and a measuring unit integrated on one base. On the base are a chinrest on the patient’s side and a printer on the operator’s side which outputs measured results. On the main body are a TV monitor and a joystick, which are used to make alignment and perform operations. The measuring unit has a measuring window into which the patient looks and where the infrared ray radiates on the patient’s eye. Also, there is an auto-tracking mechanism, which automatically moves the measuring unit up and down to follow the eye movement, and an auto-shot function, which automatically takes serial measurements when the device is in focus.