Tele Vue Dioptrx Astigmatism Correcting Lens - 2.50

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 1/4 diopter steps, from 1/4 up to 3.5 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 eyeguardsThe visual experience in astronomy is maximized by stripping away limitations:• the limitations of the observing location (dark skies and steady seeing)• the limitations of the telescope (aperture, field, resolution and contrast)• the limitations of the eyepiece (field, resolution and contrast)• the limitations of our eyesight (e.g., astigmatism)Tele Vue has historically been dedicated to overcoming the first three of these limitations:• with wide angle, flat field telescopes easily portable for traveling to great observing locations• matching ultra-wide angle eyepieces with full field image quality to generate what we call "spacewalk" viewing• and a variety of long eye relief eyepieces to allow eyeglass wearers to enjoy the maximum visual experienceTo overcome the fourth limitation (astigmatism), Tele Vue has developed a corrector which fits directly onto the eyepiece. Just as Dobsonian owners could not fully appreciate the performance of Tele Vue eyepieces until installing the Paracorr to compensate for mirror coma, the majority of the population (which has some eyesight limitations due to astigmatism) had no way to correct for this except by wearing eyeglasses. That is, until now. Introducing the DIOPTRX Astigmatism Correcting Lens Accessory, which extracts the maximum visual performance from matching eyesight to eyepiece.Tele Vue DIOPTRX lenses attach to the top of all long eye-relief Tele Vue eyepieces to compensate for eyesight astigmatism and are available in diopter steps, from 1/4 diopter up to 3.5 diopters.DIOPTRX lenses will apply to all Tele Vue eyepieces recommended for digiscoping (because of their long eye relief):• 31mm Nagler type 5• 26mm Nagler type 5• 35mm Panoptic• 27mm Panoptic• 22mm Panoptic• 55mm Plossl• 40mm Plossl• 32mm Plossl• All Radians (18mm thru 3mm) _• All Nagler type 4 (22mm, 17mm, 12mm)• 8 - 24mm Dioptrx Ready Zoom Eyepiece