Harvard University
Micro Observatory Robotic Telescope: How Does My Eye Compare to the Telescope?
Your eye is an amazing instrument--and so is the telescope! In this activity you will compare your eye's performance with that of a MicroObservatory online telescope. By the end of this lesson you will know exactly what your telescope is...
University of Chicago
University of Chicago: Reflector and Refractor
From the Yerkes Observatory Virtual Tour web site. Compares and contrasts reflecting and refracting telescopes. A link from the page leads to a second page which explains why most modern research telescopes are reflecting telescopes.