The RM-850 suits eye clinics and optometry practices that measure refraction for one patient at a time. Sphere, cylinder and axis describe the lens power that corrects the eye, and the instrument reports them across a defined range: sphere from −30 to 30 D, cylinder from 0 to 12 D and axis from 0° to 180°. Steps of 0.01 D for sphere and 0.12 D for cylinder let the readings follow the eye closely.
Autofocus with Y-axis auto tracking carries the workflow. The operator brings the instrument to the eye with the joystick; the instrument follows the eye, holds focus, and completes the measurement within 0.5 seconds. For the patient, this means holding still for a moment only, and in a busy test room it means the next person is seated sooner. The operator can read the result on the touch screen as soon as the measurement ends.
The hardware handles positioning. The electric chinrest sets the head, the joystick operates smoothly, and pupil diameters of 2–14 mm and pupillary distances of 10–85 mm fall inside the measuring range. The 9-inch TFT capacitive touch screen displays the controls and results, and the built-in thermal printer automatically cuts each printout, so the examiner has a printed result ready to hand.
Data and display options suit rooms with their own routines. WiFi and Bluetooth data transmission are available as options, and so is a VGA external screen. Power comes from AC100–240V, 50/60 Hz mains, which lets the instrument run from a standard outlet in the examination room.