For monocular len microscope, there are indirect lighting devices such as dome lighting and arch lighting.
However, for a binocular stereomicroscope, it is structurally two light path designs.
Therefore, the lighting device like the one above can not be used as it is.
There are also a way to weaken the reflection by using the LED (flat type) with the LED pointing straight down as below.
For simplicity, there is also a method to observe by attaching a diffusion tube to the LED ring light