Carl Zeiss Meditec IOL Master
IOLMaster — Overview Mode.
Overview Mode - Alignment Prior to Measurements
O key, or the button with the magnifying glass icon, as pictured on the left. This is the Overview mode, which allows for coarse image alignment prior to taking measurements. In this mode, the patient is aligned with the IOLMaster by using the joystick (see 1 below). Vertical adjustment is made by turning the control knob. The patient's eyes should be level with the two red ring marks on the side rails of the headrest (see 2 below).
Tell the patient to look straight at the small yellow fixation light and then adjust the instrument-to-patient distance until the six light reflections on the cornea (see 1 below) appear to be in focus. The small circle of lights and the cross hairs (2) should be approximately centered in the patient's pupil. This should be done prior to taking Axial Length Measurements.