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Medical Forum / General / Vision / January 2005question about the range in progressive glasses
hi......i have a question about my new progressives, and i wanted an unbiased assessment. i have a pair of progressives that focus down to about one foot for reading. they are thin(ie, about 1 1/4" top to bottom) armani glasses. if i look STRAIGHT AHEAD, the closest i can focus is about 6 feet. if i get closer(3', 4', 5') i have to tilt my head back slightly. how close should i be able to focus by looking straight ahead? btw,,,with my older glasses that i just replaced(about 1 1/2" top to bottom), i can get as close as 2'+ while looking straight ahead, and i can get as close as 9" for reading. the change in prescription was minimal from old to new. in fact, the eye doctor just put a corrective piece of glass over my older glasses for correction. thanks > hi......i have a question about my new progressives, and i wanted an > unbiased assessment. [quoted text clipped - 13 lines] > > thanks Progressives are designed for a maximum fitting height of about 15mm-20mm depending on which progressive lens design you purchased. The fitting height is usually a few millimeters above the centerpoint of your lens. A 1.25" lens is about 31mm high. The mid point is about 15.5 mm high, and fitting height is about 17 mm high. This may be acceptable according the manufacturer specs for a short corridor lens design, but usually the taller the lens, the better vision you will have. It is not uncommon for opticians to suggest that you sacrifice vision quality for fashion (of course they never tell you that you will have to sacrifice your vision). Also, it is not uncommon for there to be a fitting problem with progressive lenses so that the are not placed in the frame correctly. You can determine this by moving the frame up or down to see if that solves the problem (you will have to do this with your hands). In some cases, if that is the problem, then the frame pads can be adjusted to move the frame, but often it means that a remake is called for. If a remake is necessary, do not hesitate to demand one from the optician. If moving the frame up or down does not solve the problem, further analysis is required. In order to better compare your old and new glasses, it would help to provide the exact before and after Rx, the old lens model and lens material, and the new lens model and material. You have already provided the frame size, but it would be best to measure the height exactly in millimeters. Your optician can provide this information to you if you are not sure. > Progressives are designed for a maximum fitting height of about 15mm-20mm > depending on which progressive lens design you purchased. The fitting height [quoted text clipped - 21 lines] > millimeters. Your optician can provide this information to you if you are > not sure. thanks, mark. i appreciate your expertice. if i may,,, i will get the exact measuremnets of both old and new glasses and post them here. i am only assuming that the opticians will try to sell me what they can,,,but ib any case it is always a good idea to get an unbiased opinion,,,even if it IS on the internet:):) my concern is that, for a new pair of glasses with very little correction, i am surprised in the difference of the visual range. i noticed the curvature of the old and new glasses to be different as well. the old has greater curvature and are thibker on the sides. they MIGHT be veralux, but i am not sure. the new are thinner on the edges. > thanks, mark. i appreciate your expertice. if i may,,, i will get the > exact measuremnets of both old and new glasses and post them here. i am [quoted text clipped - 7 lines] > well. the old has greater curvature and are thibker on the sides. they > MIGHT be veralux, but i am not sure. the new are thinner on the edges. If you have Varilux (Comfort or Panamic) and the lens is thin it might be polycarb (1.59 index). Unfortunately polycarb has very poor optical qualities compared to other lens materials, especially if Rx has a moderate or strong correction (for the distance and/or add power). This is why it is important to see your exact Rx. One way to improve the optical quality (if you have polycarb) is to switch to 1.60 Thin and Lite material (this is name that Varilux uses). Unless you need safety glasses (sports or industrial/lab use), you probably don't need polycarb. Of course there could just be a fitting problem, or the frame may be so short it is stretching the limits of lens design for the minimum fitting height required for your frame. > If you have Varilux (Comfort or Panamic) and the lens is thin it might be > polycarb (1.59 index). Unfortunately polycarb has very poor optical [quoted text clipped - 10 lines] > short it is stretching the limits of lens design for the minimum fitting > height required for your frame. i can get the prescription info tomorrow. for now,,,, the old lenses are varilux comfort. they are thin, but nowhere near as thin as the new ones. the new(problem glasses) are from lenscrafter. on the invoice it says "lenses.....superview 1.67 (plastic), progressive-mvp". the new glasses are smaller in both vertical(-1/8") and horizontal(-1/8") measurements. anyway, i will get all the info tomorrow,,,as i said. thanks again mark. > i can get the prescription info tomorrow. for now,,,, > [quoted text clipped - 8 lines] > anyway, i will get all the info tomorrow,,,as i said. thanks again > mark. It is very unlikely that your Lenscrafters are Varilux. They normally use lower quality designs. If your old lenses were Varilux and taller frames, your new ones will likely not be as good. Fortunately Lenscrafters has a 30 money back guarantee. If you want Varilux Comfort (or other Varilux) at a reasonable price, then you could try Wal-Mart Optical. In the past they have also had some good Rodenstock lenses. >> i can get the prescription info tomorrow. for now,,,, >> >> the old lenses are varilux comfort. they are thin, but nowhere near as >> thin as the new ones. the new(problem glasses) are from lenscrafter. >> on the invoice it says "lenses.....superview 1.67 (plastic), >> progressive-mvp". The 1.67 index does narrow the design possibilities down. The MVP is a trade name for Lenscrafters progressives in general, but has been linked to the Essilor Natural or Sola Visuality (plus a few other designs for certain materials,) in the past. I haven't inquired lately (within the last three years) so they may have newer designs for each material offered. >> the new glasses are smaller in both vertical(-1/8") and >> horizontal(-1/8") measurements. Depending on your old frames/lenses(plus how they align on you) and the new frame/lens design(plus how they align on you), 3 mm may be significant. The horizontal is irrelevant at this point. >> anyway, i will get all the info tomorrow,,,as i said. thanks again >> mark. >> > It is very unlikely that your Lenscrafters are Varilux. They normally use > lower quality designs. If your old lenses were Varilux and taller frames, > your new ones will likely not be as good. Free marketing for Varilux. They're good lenses, but there is life after the brochures and reps that flood doctors offices and opticians stores. Many manufacturers put out designs equal to Varilux or even better. Essilor, the owner of the Varilux name brand, even updates it's common lenses to take into account the feedback learned from the earlier release of the Varilux branded products. This is why the Natural was released well after the introduction of the very old (it's a teenager now!) Comfort lens. They are both long in the tooth nowadays. You can get away with ultra low seg hts with the newer short corridor lenses, but you will always screw with computer use. Keep the minimum frame depth to at least 1 1/2 inches if you want barely functional near and far. This applies to even the short corridor lenses. > Fortunately Lenscrafters has a 30 money back guarantee. If you want > Varilux > Comfort (or other Varilux) at a reasonable price, then you could try > Wal-Mart Optical. In the past they have also had some good Rodenstock > lenses. WalMart corporate and Walmart National Vision Centers can both get Varilux branded products at a savings. You'll still be paying for the brand name just like buying Tommy Hilfiger frames. Why not spend a few extra bucks and get a custom atoric grind with the really good Zeiss or Rodenstock free form generated lenses? The difference is noticed the moment they are put on! Carl > Why not spend a few extra bucks and get a custom atoric grind with the > really good Zeiss or Rodenstock free form generated lenses? The difference > is noticed the moment they are put on! > > Carl i don't know if lenscrafter has that, but i will check other opticians.........maybe robert marc my old prescription...... od: -6.25 - 0.75 x 180 os: -5.75 - 1.50 x 180 add +1.50 my new prescription...... od: -6.50 - 0.75 x 180 os: -6.00 - 1.50 x 180 add +2.00 lenscrafter made my new glasses thin, which i didn't want because i had problems with thins before. btw,,,they now offer varilux. > my old prescription...... > od: -6.25 - 0.75 x 180 [quoted text clipped - 8 lines] > lenscrafter made my new glasses thin, which i didn't want because i had > problems with thins before. btw,,,they now offer varilux. Your Rx is probably too strong for polycarb lens material (makes distortions appear worse), so make sure that is not what you have. You would do better with 1.60 plastic. Lenscrafters has always been able to special order Varilux, but their prices are pretty high (of course the frequently offer 1/2 price lenses). I would stay away from the Comfort if you have a very short frame. here's an odd thing i just thought of...... the new narrow glasses sit at a slightly greater angle than the older pair(ie,,,they tilt forward at the top more than the older pair). now,,,,,,when i wear these, i can see miidle range(2'>) much better if i tilt my head back. i think this means i am looking through the lenses that sit more upright if i have to tilt my head. also these new pair are VERY close to my eyes. as in,,,i get smudges in the middle of the lens from my eyes, or probably my lashes, touching the lens. I'm new here and am working on getting good progressives after unilateral cataract surgery (don't get me started!). I just had a pair of Viralux glasses made -and the vision is so distorted. My old ones were add +1.50 and these new ones are add +2.25 - could that be the reason? someone mentioned Zeiss and Rodenstock - are they better ? My old ones were great - adapted to them immediately. Thanks - Karen > I'm new here and am working on getting good progressives after > unilateral cataract surgery (don't get me started!). I just had a pair > of Viralux glasses made -and the vision is so distorted. My old ones > were add +1.50 and these new ones are add +2.25 - could that be the > reason? someone mentioned Zeiss and Rodenstock - are they better ? My > old ones were great - adapted to them immediately. Thanks - Karen What is your old and new Rx (in detail)? What your old progressive lens, and what lens material? What is the lens material on your new Varilux lenses? (don't say plastic). What model of Varilux do you have (Comfort, Panamic, etc.)? it's a bit of a complicated case. Old glasses were OD -6.50 -0.75 x 10 OS -7.25 add +1.25 they were viralux ultra-thin (nothing more specific) then, cataract surgery in left eye - right eye needs contact lens to bring to full distance, so glasses are to go on top of CL to bring left eye up to distance - OD - plano OS - 1.50 - 0.50 x 90 (was made astigmatic in surgery, I think) add +2.25 these are viralux not ultra thin do I need to know more specifics? Karen > it's a bit of a complicated case. Old glasses were > OD -6.50 -0.75 x 10 [quoted text clipped - 10 lines] > these are viralux not ultra thin > do I need to know more specifics? Karen There are several models of Varilux such as the Comfort, Panamic, etc. They are different. IN addition, each Varilux lens model comes in various materials such as the following: 1.50 index plastic (CR-39) 1.59 polycarb 1.60 Thin and Lite 1.67 Thin and Lite The higher the index, the thinner the lens for a given Rx, but the worse the optics. The only exception is polycarb, which has the worst optics, even worse than 1.67 index lenses, but has high tensile strength and high impact resistance, and is very profitable so it is often dispensed. When you want to know why your old lens is clearer than your new lens, then all information this information about the lens is needed so that one can compare apples to apples. However, the fitting process of progressives is very important, and many mistakes are often made by the optician that will affect how well progressives work. This is why progressives almost always come with a remake or exchange warranty (which is one reason they cost so much). So you may have a fitting problem that would explain the difference. In addition (although I am not an expert on this) I believe that after any surgery (including lasik and cataract surgery) the eye may change somewhat in the time right after surgery, so you may need a new exam. >my old prescription...... >od: -6.25 - 0.75 x 180 [quoted text clipped - 8 lines] >lenscrafter made my new glasses thin, which i didn't want because i had >problems with thins before. btw,,,they now offer varilux. As I suspected the distance Rx went more minus slightly blurring intermediate objects more than the old glasses, but with slightly sharper distance vision compared to the old. One of the many joys of older age. Robert Martellaro ~~~~~~~~~~~~~~~~~~ Optician/Owner Roberts Optical robopt@execpc.com ~~~~~~~~~~~~~~~~~~ "Science is a way of trying not to fool yourself." - Richard Feynman > As I suspected the distance Rx went more minus slightly blurring intermediate > objects more than the old glasses, but with slightly sharper distance vision > compared to the old. One of the many joys of older age. > > Robert Martellaro i had two new pairs made. one was a "regular" pair and these that i still have are narrow. 'i've already turned the regular pair in for redo. the problem with those was that it got blurry when i looked through the top of them. i shoot pocket pool, which means i have to bend down over the pool table, and when i look up i am looking through the top of the lens. it was blurry. it was also thin lens and not varilux. i do not recall if the intermediate distance was ok. i think it was, but i can't remember. so both pairs of glasses are giving me trouble for two different reasons. would i have the same problem if i switched to contacts? i just called the makers of the older lenses,,,,and they are veralux comforts. these new ones are thins, so i don't think they are veralux. > i just called the makers of the older lenses,,,,and they are veralux > comforts. these new ones are thins, so i don't think they are veralux. The thickness of the lens depends primarily on the material, not the lens design (although that is a factor). The thinner the lens (the higher the index) the worse the optics. However, polycarb has the worst optics of any commonly used material, even worse than thinner lenses (with a higher index). Varilux lenses come in the following lens materials: 1.50 regular plastic (CR-39) 1.59 polycarb 1.60 Thin and Lite 1.67 Thin and Lite Also available in some transitions and glass materials. For a very short corridor frame, the Varilux Panamic or Varilux Ellipse would probably be better than the Comfort. >hi......i have a question about my new progressives, and i wanted an >unbiased assessment. [quoted text clipped - 13 lines] > >thanks Six feet converts to about 183cm and requires about .50DS of accommodation to bring the object into proper focus. Our eyes accommodative ability decreases with age and zeros out at about age 55. If you are about that age I would expect that the focus at six feet would be a tad soft, depending on pupil diameter, lighting conditions, and the type and strength of the distance Rx. That's assuming a properly fit lens of course. If the change in distance Rx was towards more minus or less plus I would also expect objects at two to six feet in distance, with a straight ahead gaze, to be less clear than before. It's always fun to show my clients this because one would expect that a new Rx would not make the vision less clear at certain distances but that is exactly what happens in some circumstances. The trade-off is that the distance vision beyond twenty feet will be clearer in this example. Hope this helps Robert Martellaro ~~~~~~~~~~~~~~~~~~ Optician/Owner Roberts Optical robopt@execpc.com ~~~~~~~~~~~~~~~~~~ "Science is a way of trying not to fool yourself." - Richard Feynman wonderful.... i AM 55, and you just told me i won't be able to see my wife across the dinner table. hmmmmmm,,,maybe that's a good thing. |
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