An ophthalmological microscope system, having an illumination system that projects illumination light onto a subject's eye. A light receiving system guides returning light of the illumination light to an image sensor or an eyepiece system. An interference optical system splits light into measurement light and reference light and detects interference light generated from returning light of the measurement light and the reference light. A designation unit is used for designating an operation mode. When an observation priority mode (or an OCT priority mode) has been designated, a controller executes first light amount control that restricts light amount of the measurement light (or second light amount control that restricts light amount of the illumination light) to make total light amount of the illumination light and the measurement light equal to or less than a predetermined value.
