A teacher will want a nice microscope, capable of showing whatever needs to be shown, but not necessarily better optically than a good amateur's microscope. The teacher has some special needs, and there are affordable microscopes that meet those needs.
Unlike the photographer, the teacher might want a microscope with a built-in digital camera. This makes it quite convenient to show an entire class what is under the microscope, or to share the view with an individual student in a tutoring situation. The built-in camera will be able to record video to show at a later time, or to students in different locations.
A microscope head that can swivel around to more than one viewer is also useful in a student-teacher situation, so that the entire microscope does not need to be moved, and the student and teacher can stay in their own seats.