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 .25 diopter steps, from .25 up
to 2½ diopters, 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.