At Texas Star Party and RTMC Astronomy Expo in May and Cherry Springs Star Party in June (all 2005), I had the pleasure of evaluating over 100 subjects using our DIOPTRX™ astigmatism correctors to evaluate both the absolute performance and performance relative to their eyeglasses. I used a Tele Vue 60 with 60° diagonal and 32mm Plössl (5.3mm exit pupil) to view our DIOPTRX™ test chart. In a few cases, I was able to confirm the performance at night using a 35mm Panoptic and 12mm Nagler Type-4 on our TV NP-127 to view star clusters. Most subjects did not have their eyeglass prescriptions or know their eyesight astigmatism, but I have enough experience now to guess at a reasonable starting point in trying DIOPTRX™. Since we had 10 models it was easy for subjects to find their optimum values.

Following are some general conclusions:

1. DIOPTRX™ always works at least  as good as eyeglasses and mostly better.

2. People who dislike using glasses and have astigmatism are most pleased.

3. Some people are lucky enough to have no astigmatism and will not benefit from DIOPTRX™.

4. I found many people using progressive eyeglasses, which by definition are horrendous for observing with telescopes or binoculars.

5. Many people do not realize that they don't need their eyeglasses if they are near or farsighted and don't have astigmatism.

6. Critical observers easily detect as little as ¼ diopter of astigmatism.

7. DIOPTRX™ units can be stacked (one person had 5 diopters) to accommodate astigmatism.

8. It is easy (and analogous to focusing) to "dial in" rotation of DIOPTRX™ for optimum correction. It is virtually intuitive.

9. DIOPTRX™ units are very effective in binoviewers.

10. Night tests seem to confirm no discrepancies with our daytime tests.

11. Sharper stars and detection of fainter stars are clear benefits.

12. Choosing DIOPTRX™ values based on eyeglass prescription is generally effective.

 I was very gratified by the instant and positive unprompted reactions.

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