is a tangent scale for squint angle measurement and retinal correspondence testing - for easy testing of horizontal and vertical deviations - the Maddox cross is provided with two scales: large-digit scale for 5 m testing distance & small-digit scale for 1 m testing distance - the numbers denote the angle in degrees - in the centre of the scale is a spot fixation light which should be located at eye level exactly opposite the patient during the examination - transformer included