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Re: Barrel Distortion with New Lenses

Posted on July 27, 2011, 11:42 am by Dr. Virginia Donati

Posted in Adjusting to New Prescription, Distortion, Glasses

Kelly wrote:

Dear Doctor, I am experiencing barrel distortion with my new frames and progressive lenses. When I scan from side to side, looking at a flat surface, the surface warps and teeter-totters. The last time I changed my lenses and frames two years ago, I got the barrel distortion looking out of the top of my lenses, such that the roofs of houses, or tops of fences looked warped as I scanned by them. This time, I have got progressive lenses for the first time and the barrel distortion is apparent only when I am looking through the middle to bottom of the lenses. A few questions if you are willing: 1)I have Multiple Sclerosis . Does this make me more likely to see barrel distortion? I have balance problems and vertigo from the M.S., which makes this barrel distortion really hard to cope with. 2) I was 43 years old the first time that new frames and lenses ever gave me this problem. Is seeing barrel distortion age related? (Incidently, the first time I got this problem, my frame size was being downsized. Presently, my frame size has been upsized to accomodate the progressive prescription ) 3) Are progressive lenses more likely to cause this problem than regular lenses? My optition has never encountered anyone like me before and right away was talking about giving up on the progressive lenses. Is that the solution? 4) If my brain can adjust, then what is the longest time I should give this? 5) I have got the most expensive Digital Freeform Progressive lenses, 1.6 index plastic thin and the base curve kept the same as the last two lense changes. Is there anything better than Digital Freeform Brand? 6) My prescription is OD -4.50/-0.75 x 110 + 1.25 PD:61.00 OS: -5.75 Sph + 1.25. Does this problem have anything to do with my prescription? Thank so much for your Q&A website. This is a very disabling problem and it is good to have the availability of a second opinion. Kelly

Dr. Virginia Donati's response:

Thank you for your questions, Kelly.
To answer them respectively: I am not aware of MS being more likely to cause spectacle-distortion. Increasing age does not increase the likelihood of spectacle-distortion. It is common for patients to describe unusual visual disturbances when adjusting to progressive lenses for the first time, but not barrel distortion specifically, and you mentioned that you had experienced this distortion in your previous pair of glasses (before the progressives). With that in mind, I would not say that it is fair to blame the progressives. Although you have a moderate amount of near-sightedness, I would not say that you have a complicated prescription. I highly doubt that it is to blame. Keeping the base curves constant is a great idea, as is using a digital lens. My best guess (without seeing you) would be that it has something to do with your frame-choice, or something to do with the fit of the frame. Check to make sure that the frame is not warped in such a way that it “wraps” around your temples. Ask your optometrist to ensure that the lenses are centered correctly to your pupils, and that the frames sit correctly on your face. I would also recommend that you ask your optometrist to verify that the lenses themselves are not warped. I hope you find an answer to this frustration condition soon!
Dr. Donati

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Re: Serious Distortion with New Lenses

Posted on March 3, 2010, 1:10 pm by Dr Henry Smit

Posted in Adjusting to New Prescription, Distortion, High Index Lenses

Mike wrote:

Hi, I recently had my prescription updated and went to get a new pair of glasses but ran into some visual distortion issues. My normal optometrist (that I have been seeing since I was 10, I am 27 now) was not available at the time, so I made use of the in-house one where I was getting my glasses. The prescription [I don't have it] (which was later checked by my normal optometrist) was accurate, save for the prism. For whatever reason, She could not see it while taking the measurements. So she added the prism from my glasses that I was wearing at the time (a 1 B0 prism). The optician did the glasses. When I tried them I noticed a significant distortion of the ground immediately in front of me, it was like I was walking up a 3' hill all the time. This was looking ahead normally while walking. It was also like they were magnifying the image as well, as if I looked straight down, my body/legs appeared to be about 2' tall (I'm 6'). I made a point of wearing them for a few days to see if it was an adaptation issue but there was not noticeable improvement. At that point I went back to the opticians and they rechecked everything PD, prescription, as well as positioning of the frames on my face to no avail. They suggested that I go to my normal optometrist to double check the prescription. Which I did and ended up with: OD -800 -075 175 1.5 B0 OS -650 -050 008 1.5 B0 I took this back to the opticians and they re-did the lenses with the new prism. These were a no go as well. Same visual distortion. Again, they checked the lenses, position etc. All seemed ok. Though they noted that the base curve of the new lenses was not the same as my old ones. So they suggested that they re-grind the lenses with the old base curve to see if that would fix the situation. While it did improve the distortion it was no longer a 3' hill immediately in front of me, there was still a significant rise in the ground probably from 6 to 10' away, I would have to guess that it looked like it was about 1'-2' rise, though it was smooth not abrupt, kinda like a pronounced crown in the road. At that point I had given up on the glasses as the opticians could not provide any answers or other things to try, other then to check the prescription with my optometrist again. Which I did and ended up with the most recent prescription of: OD -775 -075 175 1.5 B0 OS -675 -050 006 1.5 B0 I have not had this made into a set of glasses yet, as I don't know what was causing the problem and I am a little leery of going through this again considering the cost of the lenses alone usually runs about $300+. The lenses they were using above were Zeiss 1.67 RI, their lab was using Essilor Kappa. The frame size was 49-19, Oakley Rotor S. My old glasses (which I am still wearing) were from Lensecrafters, the lenses are Featherweights (polycarb 1.54 RI?). Frame size 46-18, similar lens shape to the Oakleys, rounded rectangle. Old glasses prescription is: OD -750 -050 180 1.0 B0 OS -625 -050 180 1.0 B0 Any ideas what was happening? Thanks for your time.

Dr Henry Smit's response:

Mike Dear Mike I will do my best to offer some suggestions based on the information that you have given me. For starters, yours is a fairly high prescription, and high prescriptions create more distortions than lenses made in a lower prescription. Secondly, I suspect that you are a sensitive observer and that you may be bothered by induced distortions that might otherwise go unnoticed by the average observer. It appears that your new prescription is a little bit stronger, that you are wearing a slightly larger frame, that the amount of “base in” prism has increased slightly and that the axis of the astigmatism has changed slightly (going from exactly horizontal to being tipped up slightly at the outside of the frame). Each of these changes, by themselves, would probably not cause a great change in visual perception. However, these four small changes, in combination, may be enough for a sensitive observer to notice. In addition, it is possible that the “wrap” of the new frame is different that the vertical centration of the lenses may be different from what you are used to wearing. These factors could make your adaption to the new glasses a little more difficult. Fortunately, most patients do eventually adapt to changes in prescription and lens design. If you have worn the glasses for a period of a few weeks and do not experience any improvement in your symptoms, you may want to try to go back to a smaller frame. As a last resort, you may also want to go back to the polycarbonate lenses, but any improvement in spatial perception you might gain may also be offset by the generally lower optical quality that polycarbonate lenses provide away from their optical centers. I wish you luck. It sounds that you and your different care providers are doing their best to make things work for you. Hopefully with a little more perseverance you will be successful. Best of luck Dr. Smit

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Re: Blurriness in Distance Portion of Progressives

Posted on November 24, 2009, 12:50 pm by Dr Henry Smit

Posted in Distortion, Progressive Lenses

Ellen wrote:

I am 50 and I recently purchased my first pair of "real" glasses. I was tired of putting on/taking off my reading glasses 30 times a day! I decided to get progressive lenses. My Rx for distance is very minimal and my reading Rx is 2.0. The biggest problem with the new lenses is that the distance portion of the lens is quite blurry. I can see distances much more clearly without the glasses. Is this a common problem with progressives or could there be a problem with the lenses? The other problems I am having seem to be the same as other posters on the message board (distortion in the outer portion of the "reading" area. Any advice would be appreciated!

Dr Henry Smit's response:

Dear Ellen Your reaction to your first pair of progressive lenses is not uncommon, in fact, it is quite typical. Assuming that your prescription is correct and that the glasses were fitted correctly, even a good quality traditional progressive lens will have some distortion outside of the reading area in the lower part of the glasses, and a certain measure of blur on the outside edges of the distance (top) portion of the lenses. Great strides have made in the past few years to minimize these areas of distortion, but new this technology is not necessarily incorporated into every new pair of lenses. I suspect this is because the technology is significantly more expensive than traditional progressive lenses which were used in the past, and are still in use today. I would suggest that if you are not starting to adapt to your new prescription after a trial period of a week or so, that you return to the place where you purchased your glasses and describe the difficulties you are having. The may be able to offer you an alternate lens design that you may adapt to more easily. Best of luck. Dr. Smit

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