Abstract: An opthalmic microscope is provided having a variable shutter illumination system which decreases the amount of light from the light source passing through the shutter to the field of view. When a patient's eye is positioned within the field of view, the variable shutter acts to decrease the exposure time the illumination beam contacts a patient's retina. In a first embodiment, the variable shutter includes a rotating disk having at least one controllable operative where such disk is placed between the illumination source and the field of view of the microscope. In another embodiment, the variable shutter is provided by an electronically controlled liquid crystal shutter which is operable between a fully open position allowing substantially all of the light beam to pass therethrough to a fully closed position totally blocking the transmission of light through the shutter.