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Medical Forum / General / Vision / April 2006Another Progressive Lens Recommendation Request
Hi, I'm looking for advice on a progressive lens brand. I'm 53 years old, have worn progressives fairly successfully about 4 years and not so successfully 3 years before that. My rx is: -6.75 0 0 +2.25 -4.25 50 40 +2.25 I don't seem to have much flexibility for where I can focus, and after a lot of experimenting, found that I'm much more comfortable if I wear reading glasses for any amount of reading, and compter glasses for working at my PC. But I like having progressives so I don't have to take off my distance glasses for things like reading menus, labels in stores, the display on my cellphone, etc. I gave up on several pairs of progressives until I tried high-index Varilux Comfort, which I've worn ever since. But I wonder if there's something even better for distance vision. Could someone who's knowledgeable about the better lens brands recommend the one that's best (and has the biggest area) for distance? I don't care if the near areas aren't as big, since I never use them for serious focusing. The opticians here don't seem as knowledgeable as some in this group. Thanks in advance. Oops, my rx is: My rx is: -6.75 0 0 +2.25 -5.25 50 40 +2.25 not 4.25 as I wrote. > Hi, > [quoted text clipped - 23 lines] > > Thanks in advance. > Hi, > [quoted text clipped - 23 lines] > > Thanks in advance. I would look at the high end Rodenstocks that are custom ground to your Rx. Most other lenses are made in one of 4-5 base curves, and the ground to your Rx from that, but the base curves are not always optimal for any given Rx. > Hi, > [quoted text clipped - 23 lines] > > Thanks in advance. I switched about 18 months ago from the Comforts to J&J Definity, after about a year of searching. My prescription is similar to yours, with greater astigmatism. I couldn't be happier. They have to be ground at J&J, though that may change since I understand that Varilux was buying them out. Not many prescribers carry them, but if you can find one, that might be a good choice. I teach and spend a great deal of time on the computer. I first intended to use separate computer lenses, but the transition is so smooth from near to far, and so wide with little distortion, that I find these excellent for computer use as well.  SignatureDennis Roark denro@sio.NOSPAMmidco.net Starting Points: http://sio.midco.net/denro/www > I switched about 18 months ago from the Comforts to J&J Definity, after > about a year of searching. My prescription is similar to yours, with [quoted text clipped - 5 lines] > transition is so smooth from near to far, and so wide with little > distortion, that I find these excellent for computer use as well. Definity is now owned by Essilor. Varilux is just one of the brand names owned by Essilor. At least so far, it appears that Definity will be marketed under its own brand name (not Varilux). The Definity splits the add power over the front and back surfaces of the lens, and needs to be made on specialized equipment designed for that purpose. So, even thought they are now owned by Essilor, the are still made on the same equipment. Definity claims that splitting the add power on the front and back surfaces on the lens produces less peripheral distortion than most other progressive lenses . Another unique features of Definity is that there is a reduction in power below the reading zone, which would help you looking down where you are walking. It also features a wide intermediate zone, which would be good for many computer users. Definity is one the lens designs that should be considered by anyone looking at a premium lens design, in addition to the others already mentioned. There are about 200 distributors in the US that carry Definity, so any independent optical shop or OD can get them. Sometimes even independent optical are lazy and only like dealing with certain labs, but you should be able to find someone who will order them for you, especially if they deal with other Essilor/Varilux products. > Definity is now owned by Essilor. Varilux is just one of > the brand names owned by Essilor. At least so far, it [quoted text clipped - 6 lines] > they are now owned by Essilor, the are still made on the > same equipment. Any thoughts/opinions/feedback on the Physio 360? -Quick If you have been happy with comfort lenses, then a switch to panamic should do the trick. There is better peripheral vision and a slightly shorter corridor. Essilor wouldn't release a lens after comfort until they came up with something significantly better - the Panamic was it. All my comfort wearers are now wearing these happily. dr grant > If you have been happy with comfort lenses, then a switch to panamic > should do the trick. [quoted text clipped - 5 lines] > > dr grant Panamic is on it's way out. Was a dud and will not be available much longer. w.stacy, o.d. Is there something else you'd recommend? I know I have to talk to a good optician, but there aren't very many nearby, and I'd really like to go in with at least a good idea of something to ask about that would give me the best distance vision. Thanks, Ellen >> If you have been happy with comfort lenses, then a switch to panamic >> should do the trick. [quoted text clipped - 10 lines] > > w.stacy, o.d. >Hi, > [quoted text clipped - 23 lines] > >Thanks in advance. Gradal Top/Zeiss and Genesis/Shamir are essentially one two for distance peripheral sharpness and comfort. Don't use poly or index over 1.60. Hope this helps Robert Martellaro ~~~~~~~~~~~~~~~~~~ Optician/Owner Roberts Optical ~~~~~~~~~~~~~~~~~~ "If a million people believe a foolish thing, it is still a foolish thing." - Anatole France Hi, Thanks, yes it does. I was hoping to get a reply from you. I'll try to get one of those 2 brands. I knew about not getting polycarbonate, but not about higher index, so I'll add that to my list. Thanks again, Ellen > Gradal Top/Zeiss and Genesis/Shamir are essentially one two for distance > peripheral sharpness and comfort. Don't use poly or index over 1.60. [quoted text clipped - 9 lines] > thing." > - Anatole France >Hi, > [quoted text clipped - 21 lines] >> thing." >> - Anatole France Ellen, The Zeiss lens should be readily available and would be my first choice. The problem with indexes over 1.60 (one possible exception-Hoya's 1.70) is that they have higher dispersion (lower abbe numbers) than other materials. If the lens power is strong enough, there will be some degree of blur as you look away from the lens center. The amount of blur is determined by the amount of prism induced (power times distance) divided by the materials Abbe number. The formula is TCA= P/V where TCA is trans (lateral) chromatic aberration, P is prism, and V is the material's Abbe number. Jalie has written that .10 prism diopters is enough to be a concern, and Torgersen says that .16^ is enough to decrease acuity by one line. That seems to correspond with my personal experience (my Rx is -4.50) and from feedback from my clients. However, some folks don't find this to be too much of a problem, depending on the degree of blurring of course, and may be partially due to how sensitive one is to these aberrations, and to how often and how far one looks or needs to look off-axis. Single vision lens wearers can turn their head and avoid the blur for instance, with multifocal wearers being forced to look down and away from the lens center 10mm to 15mm (or more) to reach the near focus. You have stated a preference for the best possible distance off-axis/center vision and tend to use separate glasses for extended near tasks. In this case I would look for ways to decrease TCA as well as minimizing oblique astigmatism and power error. Using your Rx for the right eye (-6.75), a lens with an Abbe of 32 induces .17^of TCA when the gaze is 8mm from the lens center, enough to cause noticeable blur. Changing to a 42 Abbe lens (1.60 index of refraction) decreases TCA to .13^, much less likely to be noticeable. Robert Martellaro ~~~~~~~~~~~~~~~~~~ Optician/Owner Roberts Optical ~~~~~~~~~~~~~~~~~~ "If a million people believe a foolish thing, it is still a foolish thing." - Anatole France "Robert Martellaro" <robopt@nospam.com> wrote in message .. > <snip>. > Changing to a 42 Abbe lens (1.60 index of refraction) decreases [quoted text clipped - 4 lines] > Optician/Owner > Roberts Optical Which brands of 1.60 have an abbe of 42. Does that include Varilux (Essilor)? >"Robert Martellaro" <robopt@nospam.com> wrote in message .. >> <snip>. [quoted text clipped - 8 lines] >Which brands of 1.60 have an abbe of 42. Does that include Varilux >(Essilor)? I'm pretty sure all of the major manufactuers have switched to 42 Abbe 1.60 index. Mitsui Toatsu Chemical supplies most of the industries hi-index materials. The MR-6 material was the old 1.60 that had an Abbe number of 36, the latest is MR-8 with an Abbe of 42. Thanks to everyone for the helpful info and recommendations. I really appreciate it! |
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