It is our experience that so called "toy microscopes" are a real disaster because they commonly give little more than diffuse images or shadows. This can cause a young person to lose all interest in these instruments.
Milkwood Nick wrote:
Microscope work needs a bit of training. Our scope is a $600 binocular model powerful enough to see individual soil bacteria. Not sure if it's worth it for the average farmer/gardener, but it has a high cool factor