The Center for Molecular Biotechnology Outreach Program at the University of Washington has chosen to publish its series of lesson plans on the web. Basic biological lessons follow, with student-prepared onion skin and pond life samples, plus an introduction to cells using purchased prepared slides. The third segment, a good introduction to DNA, doesn't use microscopy.
Good use is made of measurement, math, and graphing.
The activities can be used singly, or they can be used in sequence as a curriculum unit on optics. The cost is low, but the quality is high. There are copyable worksheets and advice on assessment. The projects could provide a curriculum unit or enrichment for individual students who develop an interest in optics. For grades 5-6.