Provided is a novel technology that can improve the image quality of observational images and OCT images while providing protection from light hazards, even when an OCT device has been combined with an ophthalmological microscope. The ophthalmological microscope system according to the embodiments includes an illumination system, a light-receiving system, an interference optical system, a designation unit, and a control unit. The illumination system emits illumination light at an eye under examination. The light-receiving system guides return light that is from illumination light that has been emitted at the eye under examination to an imaging element or to an ocular lens. The interference optical system separates light from an OCT light source into measurement light and reference light and detects interference light between the reference light and return light that is from measurement light that has been emitted at the eye under examination. The designation unit is used for designating operation modes. When an observation-prioritizing mode has been designated, the control unit performs first light-amount control that limits the amount of measurement light such that the combined amount of illumination light and measurement light is at or below a predetermined value. When an OCT-prioritizing mode has been designated, the control unit performs second light-amount control that limits the amount of illumination light such that the combined amount of light is at or below a predetermined value.L'invention concerne une nouvelle technologie qui peut améliorer la qualité d'image d'images d'observation et d'images OCT tout en fournissant une protection contre des dangers de lumière, même lorsqu'un dispositif OCT a été combiné à un microscope ophtalmologique. Le système de microscope ophtalmologique selon les modes de réalisation comprend un système d'éclairage, un système de réception de lumière, un système optique d'interférence, une unité de désignation, et une unité de com
