The bon OM-1 Javal Schiotz type ophthalmometer measures: Corneal curvature and refraction. Extent and axis of astigmatism. The single handle base control of the OM-1 is both simple and practical to use allowing quick and accurate measurements. The mires are configured to the Javal principle with complementary red and green filters. The point of intersection becomes white allowing very precise positioning and a significantly greater accuracy of measurement. An illuminated fixation target draws the gaze of the patient automatically towards the optical axis of the ophthalmometer.