Early laboratory microscopes consisted mainly of a tiny hollow tube. You dribbled oil (clear sperm oil was prefered for the first century) down the tube until a lens "happened" at the bottom end.
Some of these kind were still in a few pharmacy (drug store) "labs" when I was a kid, so they must have worked reasonably well, although the old town doc claimed they were the reason he learned to "cuss." (He probably used a stronger word with the older folk - I know that he knew a lot of them.)
A gallery in my area was touting a display for a guy who specialized in "pin hole pictures" recently. There appear to be several "names" in that field who are currently or recently active.