Slide 5 of 19

Notes:

• To illustrate the practical problems that currently exist in our field, I will digress momentarily to present a "case study in confusion". Last summer, Applegate and I wanted to compare results obtained with the venerable Howland crossed-cylinder aberroscope against the new Shack-Hartmann method for measuring the eye's aberrations. We were immediately confronted with a long list of questions listed on this slide.

  Read & elaborate each question.

  The last question is especially troublesome. Ray's favorite question is "Where is the gold standard in our field? Where is the model eye with known aberrations that we can use to can calibrate our aberrometers? "

  In the absence of a gold standard, Applegate built a physical model eye which I will tell you about in a moment. But first, let me give you some concrete examples of how the the problems identified on this slide can rear their ugly heads and impede progress.