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Medical Forum / General / Vision / February 2006problems with buying prescription specs
I moved to Australia from the UK almost a year ago and have yet to find an optician who can make me specs that I can see out of! My prescription is: sph cyl axis R +8.00 - 2.50 25 L + 7.50 -2.50 168 I have never had problems buying specs before and have worn specs for 28 years in the UK. I have transitions lenses also. I have had 4 pairs made up in OZ and the vision in 2 of them was so bad it was like looking through a goldfish bowl. The 3rd pair was better - left eye ok but right eye MAJOR distortion all over. They took some measurements and made adjustments. The 4th pair is better - left eye ok - right eye still a problem. I have major distortion on the left hand side only (by my nose) so that over a cm of the lens is blurred and makes using the specs impossible (almost crashed the car when I tried them as I couldn't see the car coming .....) I think they have tried high index aspheric lenses but they claim that my old pair (from the UK) are these too, and that I should be able to see clearly. I don't know what my old specs are but I think they are a different material as the magnification feels different, and they weigh slightly more than the new pair. I am at a loss of what to do - 3 opticians and I am still without new specs! Given that they cost a lot more here than the UK I need to make sure that the pair I get are right. Can anyone advise what to try next? >I moved to Australia from the UK almost a year ago and have yet to find > an optician who can make me specs that I can see out of! My [quoted text clipped - 27 lines] > > Can anyone advise what to try next? These are very strong lenses. You should do whatever it takes to find out what lens brand and lens material and index you had before and post the info here (I assume you still have them). You can also post what they are now recommending. Above all else, avoid polycarb like the plague. They are terrible with very high plus lenses like yours. High index is a very vague term, and can mean anything from 1.59, 1.60, 1.67. 1.70, etc. The higher the index, the worse the optics, expect for polycarb which has the worse optics of any of them at 1.59 index (but is considered to be a safety lens).. With very high power aspheric lenses, a good fitting is very important, and if not done properly it could be the source of your problem. You can sometimes figure out if the fitting is the problem by moving the frame around on your face to see if the vision improves. Sorry to pester - I really am grateful for ANY comment/suggestion. The brand of lenses that the recent optician has used is Sola and they are spectralite 1.54 index transitions. He wants to remake some lenses using standard lenses with a 1.5 index as he thinks that without the aspheric component, the vision should be better. I will call the UK in a few hours to see if I can can find out what my old specs are. Oh bother! > Sorry to pester - I really am grateful for ANY comment/suggestion. > [quoted text clipped - 4 lines] > a few hours to see if I can can find out what my old specs are. Oh > bother! Spectralite is 1.54 index and is considered mid-index. Spectralite has excellent optics and I don't think you will improve much if you get regular plastic 1.5 index (AKA CR-39 hard resin). Both Spectralite and especially 1.5 regular plastic are going to be fairly thick in a +8 lens. But there are potential problems in terms of optical quality (chromatic aberration measured in abbe value) if you go to a high index lens. However, it they are a good design and fitted properly, you should be able to wear a high index design (especially if you stay away from polycarb). High index will take a little getting used to compared to your present lenses, and you may encounter a slight "swim" effect (even for SV lenses) with a +8 in a aspheric design. However, the problems you are now encountering appears to be a very poor fitting or a badly made lens. Try moving the frame around to see if that helps (indication of bad fitting). If just one lens is bad, then that is strong indication of poor fitting and/or badly made lens. Perhaps some others can recommend a specific lens for a +8 that will minimize distortion (if made and fitted properly). >Sorry to pester - I really am grateful for ANY comment/suggestion. > >The brand of lenses that the recent optician has used is Sola and they >are spectralite 1.54 index transitions. He wants to remake some lenses >using standard lenses with a 1.5 index as he thinks that without the >aspheric component, the vision should be better. The primary reason for using aspheric curves is to allow the use of flatter base curves, improving the appearance and decreasing the weight and magnification without increasing oblique astigmatism (off-axis blur). A +8.00DS on a +8.00 BC (base curve) 1.54 index material will have about 1.50DC of oblique astigmatism when the gaze is15mm off-axis. Using an aspheric design can reduce that to less than .25DC with about the same mean power error. To get the same quality off-axis optics without asphericity would require a +13.00BC, a terrible looking lens with a significant increase in thickness/magnification. Aspheric lenses require precise lens positioning. Make sure that the optician is measuring monocular PDs and dropping the OC (optical center) 1mm for every two degrees of panto, assuring that the principal axis of the lens passes through the eyes center of rotation. Each lens should have the OC ink dotted and then checked to see if they are positioned properly in front of the eyes. Hope this helps Robert Martellaro ~~~~~~~~~~~~~~~~~~ Optician/Owner Roberts Optical robopt@execpc.com ~~~~~~~~~~~~~~~~~~ "An expert is a person who has made all the mistakes that can be made in a very narrow field." - Niels Bohr > Can anyone advise what to try next? Contacts. No kidding. -MT Re: contacts - used to use them over 10 years ago but after a year I made mistake of using the combined pill - my eyes are now intolerant to contacts (I tried them again a few years ago and within an hour my eyes are bright red blood shot and very painful). > Re: contacts - used to use them over 10 years ago but after a year I > made mistake of using the combined pill - my eyes are now intolerant to > contacts (I tried them again a few years ago and within an hour my eyes > are bright red blood shot and very painful). None of which rules out contacts if you find someone with the experience and expertise to fit them. But, shelving the idea of contacts... The distortions you describe with glasses are virtually absent in contacts, because the distortions are multiplied by the distance off your eye, and to a lesser degree the thickness and curvature of the lens you use. So to minimize distortion in glasses, you'd want lenses as much like contacts as practical. For the most part that means closely fit to your eyes, and small-diameter frames so the lenses can be thin. These two factors (vertex distance and thickness) can easily be more important than the material or brand of lens you use. A magnifying glass doesn't magnify (or distort much) when it's touching the page. The more it's separated off the page, the more mag and distortion you get. -MT Yeah, I get the magnification bit. I find it strange that only one edge of the specs is distorted. If I can't find an optician that makes specs ok, what chance of I got of finding one that makes contacts??? Plus, again, they are expensive here (UK did free trials too) I have been told that my old prescription lenses were standard transitions lenses, not hi index, not aspherics, nothing was done to them to make them thinner. They were a standard specsavers lens. The new lenses were made with sola spectralite (hi index) transitions with index 1.54 and aspheric. I was told that this would make them thinner. My optician now wants to try a sola transitons lens with index 1.5 but not aspheric. A different optician has recommended a hi index 1.6 aspheric. Another had recommended a hi index hoya 1.7 aspheric lens. Still confused as to what to do. One says that aspheric will add to distortion, another says it will decrease it. > I have been told that my old prescription lenses were standard > transitions lenses, not hi index, not aspherics, nothing was done to [quoted text clipped - 10 lines] > Still confused as to what to do. One says that aspheric will add to > distortion, another says it will decrease it. Aspheric will result in a thinner & flatter lens with better quality vision than a conventional (spherical) lens, BUT only if it is manufactured correctly - i.e. with the optical centres of the lenses positioned correctly with respect to your pupils (both vertically & horizontally). An aspheric lens that is not centered correctly will potentially give you worse vision than a conventional (spherical) lens. If only one side of the lens is distorted this suggests to me that the horizontal centration of the lenses is out. Spectralite 1.54 is an excellent material and in my opinion that is definitely the material that I would recommend for you, in a frame that is as small as possible, and with accurate measurements. Standard 1.5 index plastic (spherical) is more forgiving of sloppy measurements but is thicker and less attractive. However it would be my second preference after spectralite. 1.6 and 1.7 lenses would be a little thinner than spectralite but with noticeably worse quality optics so I wouldn't recommend these. Contacts could really be great for you but you still need to get your glasses right so you have something to wear when you're not wearing contacts. Are you sure the prescription you are using is correct in the first place? Also, where are you in Australia? (I may be able to recommend someone near you). Having worked in optics in both the UK and Australia the skill level in Australia is on par but it sounds like you've been unlucky so far. PS. Trivial Detail: In Australia it is "Optical Dispenser" rather than "Optician" which sounds very quaint and old fashioned to Australian ears!! Dom >Yeah, I get the magnification bit. I find it strange that only one >edge of the specs is distorted. If I can't find an optician that makes >specs ok, what chance of I got of finding one that makes contacts??? >Plus, again, they are expensive here (UK did free trials too) Your Rx and mine are not terribly different ... poor bastard ;-) The doc's here are right on two counts: - You need an excellent optometrist (forgive me if this terminology doesn't translate exactly in OZ)--preferably a low-vision specialist who works with strong prescriptions like ours. These are people who understand all of the particular optical physics (pantographic tilt, vertex distance, placement of lenses within the trial frames, optical center locations, etc.) very well and are really quite meticulous in their prescribing and fitting. - I totally agree with Mike Tyner (no surprise there): contacts. There are dramatically new materials and options than there were ten years ago. The decrease in optical 'noise' from glasses to contacts is awesome. The peripheral vision is awesome. The ability to wear your choice of sunglasses is awesome. Additionally, for high hyperopes (that's us), you need less accommodation when looking through contacts than you do when wearing glasses. This can lessen eyestrain. Try to find a low-vision specialist. Tomorrow, I drive two hours for a contact lens fitting ... in the legendary Southern California traffic ... to go to the best place I can find. It's worth it. Best of luck, Mate. Seriously. I feel your struggle ;-)  SignatureLive simply so that others may simply live Neil Brooks put fingers to keyboard and typed... > Additionally, for high > hyperopes (that's us), you need less accommodation when looking > through contacts than you do when wearing glasses. This can lessen > eyestrain. I think you may be talking about the induced base out prism with glasses, if anything you have to accomodate more with contacts, you can always have your glasses lower down your nose for reading. SignatureShabs. >Neil Brooks put fingers to keyboard and typed... > [quoted text clipped - 6 lines] >if anything you have to accomodate more with contacts, you can always have >your glasses lower down your nose for reading. Not to my understanding. Though you're likely correct about the "lower down your nose" thing, that introduces a variable. All the research I've ever seen indicates that hyperopes acc. less with cl's, and that myopes acc. more with cl's. I'd be more than interested if you have any citations that point to the opposite conclusion.... 1) http://www.revoptom.com/archive/issue/ro06f2.htm 2) Sampson WG. Correction of refractive errors: Effect on accommodation and convergence. Trans Am Acad Ophthalmol Otolaryngol 1971;75:124-32. 3) http://www.revoptom.com/archive/issue/ro09f7.htm 4) http://www.optometry.co.uk/files/16b584a2c9ab1d496644a3d8e3b2184c_bansai20040924.pdf OR http://snipurl.com/mbij SignatureLive simply so that others may simply live Neil Brooks put fingers to keyboard and typed... > Not to my understanding. > > Though you're likely correct about the "lower down your nose" thing, > that introduces a variable. All the research I've ever seen indicates > that hyperopes acc. less with cl's, and that myopes acc. more with > cl's. You are absolutely correct of course, for some reason I thought we were talking about a (pre-)presbyope (must have gotten mixed up with another px.) SignatureShabs. Thanks for the advice. My gut feeling is that the opticians I have been to in OZ don't know how to measure accurately (big hint: present lens got better when different measurements were taken). From what people have said to me, I also think that this last problem lens probably hasn't been manufactured properly. My current specs appear to be CR-39 - slightly heavier than the 1.54 spectralite, slightly thicker, and with greater magnification. I say the word 'slightly' because I really don't notice much of a difference except for the magnification, which isn't extreme and has benefits when driving, watching TV from a distance, sewing, etc. I'm debating whether to just have some lens made of the same material again or change opticians for the 5th time in 12 months. Unfortunately, I don't know of any low vision specialists to help as I'm still quite new here (Launceston, Tasmania). I also assume the optician who made me the 'fish bowl vision' lenses (specs no.3 made in the past 12 months) used polycarbonate - dur. Even I know not to use that for my prescription! >Unfortunately, I don't know of any low >vision specialists to help as I'm still quite new here (Launceston, >Tasmania). I also assume the optician who made me the 'fish bowl >vision' lenses (specs no.3 made in the past 12 months) used >polycarbonate - dur. Even I know not to use that for my prescription! I've never been to this place (primarily because I live, literally, thousands and thousands of miles from there), but ... I found these guys: http://www.eyelines.com.au/pages/about.html 61 Brisbane Street. Phone 6331 7513 Their website lists them as proficient with low-vision optometry. Know of them? SignatureLive simply so that others may simply live > Thanks for the advice. My gut feeling is that the opticians I have > been to in OZ don't know how to measure accurately (big hint: present [quoted text clipped - 12 lines] > vision' lenses (specs no.3 made in the past 12 months) used > polycarbonate - dur. Even I know not to use that for my prescription! Have you tried these people: http://www.optomeyes.com.au/index.htm Andrew Hogan I believe is very good... but he is one of the optometrists (who tests your eyes) rather than an optical dispenser (who makes the glasses). Dom Thanks to all the advice - I had just had my 6th pair of specs made up (CR39 as that is what my currecnt usuable pair are) and they do not work either! Judging by teh distortion on one side I think the mesurements are very wrong. Going to try some of the opticians suggested above next. Problem with +8.00 is ther eis little other than CR39 to make lenses out of. Spectralite is as good as cow-dung and high index lenses just don't go that high. What you need to do is copy the old Rx PD, tilt Vertex distance etc so you can adapt. Ultimately the mein problem is with you adapting to the aberrations, assuming the lenses are made correctly. One of the problems we face as optoms is making a great set of glasses, only to find the patient not adapting due to crappy old glasses and having adapted to them and not being able to change to the new set. As much as we want to make new and beter glasses, sometimes you have to stick with the old design because that is what you are comfortable with. dr grant Hi, Just come into this thread, but looking through my lens catalogues (NB there are UK listings) Seiko SSV aspheric 1.67 index goes to +16.00 cyls to -6.00DC on a 60 uncut Pentax 1.67 Aspheric +8.00 with cyls to -5.00 on a 65 uncut Pentax 1.60 aspheric +8.00with cyls to -5.00 on 65 uncut Seiko Super 16 +8.50 cyls to -6.00 65 uncut In CR39 several types of aspherics So for thin lenses on this side of the pond should not be a problem. I would have thouht that Seko and Pentax would be available world wide. Regards Ian Hodgson - Isle of Man > Problem with +8.00 is ther eis little other than CR39 to make lenses > out of. Spectralite is as good as cow-dung and high index lenses just [quoted text clipped - 11 lines] > > dr grant
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