My mom was a lab tech in a doctor's office, and I remember looking through the binocular microscope in the lab. She used to let me look at things like blood samples and so forth. I even learned how to do a white blood count from a slide! Those were the days when you had to do a lot of that stuff manually, and didn't send it off to a lab, or put it in a machine.
I saw a trinocular microscope in a medical supply catalog she had and thought it was really cool looking. I didn't wonder then what it was used for, but I do remember thinking it looked rather alien.