Product Description

Got astigmatism? Get the "cure".

Your telescope's focuser is used to compensate for your near- or far-sightedness; DIOPTRX™ compensates for your astigmatism. These units attach and lock onto the tops of over 20 long eye-relief Tele Vue eyepieces to achieve the sharpest full-field viewing possible. DIOPTRX™ models are available in ¼ to 3½ diopter and are rotatable for tuning to the best orientation. A series of engraved letters on the barrel helps to monitor orientation. Simply choose the DIOPTRX™ model that matches your eyeglass prescription for astigmatism. All lenses are multi-coated glass in anodized aluminum housings with rubber eyeguards.

Benefits of using Dioptrx over eyeglasses

• 1. You're more likely to see a sharper, higher contrast image, because:
• A. The Dioptrx is always completely aligned to the eyepiece optics, eliminating aberrations from a decentered mismatch of eyeglass power and astigmatic axis.
• B. Dioptrx can be rotated to exactly compensate for the astigmatic axis angle in real time, since both head angle and age can vary your eyesight astigmatic angle.
• C. Dioptrx likely has better multi-coatings than eyeglasses, and certainly is better in transmission and reflection reduction than uncoated eyeglass.
• D. Dioptrx is more likely to be cleaner than eyeglasses, which may have scratches and smudges from constant use and wear and tear.
• E. Dioptrx allows seeing your normal maximum contrast that eyeglasses can diminish (remove your eyeglasses and see how contrast improves in normal vision).
• 2. You're more likely to see the full field in 100° Ethos eyepieces because your eyeglasses are more limiting in "effective eye-relief".

Al's Star Party Report

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:

• DIOPTRX™ always works at least as good as eyeglasses and mostly better.
• People who dislike using glasses and have astigmatism are most pleased.
• Some people are lucky enough to have no astigmatism and will not benefit from DIOPTRX™.
• I found many people using progressive eyeglasses, which by definition are horrendous for observing with telescopes or binoculars.
• Many people do not realize that they don't need their eyeglasses if they are near or farsighted and don't have astigmatism.
• Critical observers easily detect as little as ¼ diopter of astigmatism.
• DIOPTRX™ units can be stacked (one person had 5 diopters) to accommodate astigmatism.
• It is easy (and analogous to focusing) to "dial in" rotation of DIOPTRX™ for optimum correction. It is virtually intuitive.
• DIOPTRX™ units are very effective in binoviewers.
• Night tests seem to confirm no discrepancies with our daytime tests.
• Sharper stars and detection of fainter stars are clear benefits.
• Choosing DIOPTRX™ values based on eyeglass prescription is generally effective.

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