More Comments Received
Apparently I’m not the only person with problems with my bifocals. Click here to read more comments and emails I’ve received.
Apparently I’m not the only person with problems with my bifocals. Click here to read more comments and emails I’ve received.
June 8th, 2006
Thanks for the info. This was very helpful. I’m just now trying to get used to my second pair of progressive lenses.
They already had to remake one lens due to a defect in the lens. I’m still having trouble, especially with the
computer, which I use most of the day.
October 27th, 2006
Thanks for the info. I recently returned the third pair of bad progressives that I have had in the last five years. It was very helpful to read that “focal point in the wrong place” is so common (an issue I was dealing with with my last pair for three months). The optometrist adjusted my prescription, but the lab kept returning lenses that were off center. Finally I had to give up. I agree that I too have had my best experience with an opthamologist at a small, expensive place. It’s back to the opthamologist for me. My eyes are too important to fool around with the cheap places anymore.
January 3rd, 2007
Excellent website. I have taken a quick look around and most of the information is current and accurate. I am just reaching the presbyopic stage of my life (I turned 49 recently and I am noticing a profound reduction in my accommodative ability). About ten years ago I ran an optical laboratory preparing wholesale ophthalmic lenses for optometrists and opticians as well as completing the optician’s course (I never bothered getting licensed as it was unnecessary for my purposes). All of this to tell you that I do know a bit about this - although it has been some time since I have had to retrieve the information from my tired old memory banks.
Regarding some of your problems with PALs, there are several factors that are vital in the fitting of the lenses. A good optometrist or optician will ensure they are dealt with. Some of these issues are:
- The fitting height is crucial in order to ensure that the pupil is correctly aligned with the optical centre of the lens.
- Also crucial is the PD (inter-pupillary distance) - usually measured monocularly (i.e. from the bridge of the nose to the centre of each pupil. This is what is measured by the PD device (the binocular-looking device).
Due to the continuously varying shape of the front surface of a PAL it is very important that the lenses be precisely fitted both horizontally and vertically. The should be worn as close to the face as possible (if you have long eyelashes this can present a problem with oily smudges on the back of the lens. Without knowing anything about your personal situation and certainly not trying to produce a diagnosis you may also be sensitive to the prism induced by tilting the lenses (either down or up). As you correctly noted there are many brands of quality PALs and each is designed differently. You may have to try several to find one that you like.
A small point of information. So-called “plastic” lenses are made from CR-39 a polymer resin produced by PPG Industries. The vast majority of ophthalmic lenses are made from this material. In the industry CR-39 is the generic name for what are commonly called “plastic lenses. Regarding polycarbonate lenses (Lenscrafter’s FeatherWates and others) they have several key features. It is a high index material (~1.585) relative to CR-39’s (1.452). Higher refractive index (RI) materials “bend” light more efficiently than low RI materials hence can be made thinner in high powers. This higher RI usually comes at a cost and that is chromatic aberration. This results from the material having a different RI for differing wavelengths of light. It is measured by the Abbe number. Higher Abbe is better (i.e. less chromatic aberration). This is manifest to the consumer through colour fringes on objects as the images at each wavelength is displaced. Polycarbonate has the lowest Abbe value (at 34) of any common ophthalmic lens material. Compare it to CR-39’s 59.3 and it becomes clear why polycarbonate lenses have a reputation for poor optics.
In a nutshell here are the relative advantages and disadvantages of polycarbonate (PC) versus “plastic” CR-39:
Pro
- It is less dense (~1.21 g/cm3) vs 1.31 g/cm3 for CR-39
- It has a (relatively) high RI (~1.585) vs 1.452 for CR-39
- This results in lenses that are thinner and markedly lighter than CR-39 particularly at higher powers
- It is almost unbreakable (used in safety glasses)
Con
- It is the softest (i.e. likeliest to scratch) material used for ophthalmic lenses. An uncoated CR-39 lens is less likely to scratch than most scratch-coated PC lenses
- It has a very low Abbe number (34) vs CR-39’s 59.3
Indications
- Children and others who require maximal impact protection
- Those that can tolerate the chromatic aberration and need the light weight in higher powers
Contraindications
- Low to medium powers - the weight/thinness benefit is marginal at these powers
- Those sensitive to chromatic aberration
- Abrasive environments - they scratch easily
- Environments with solvents - acetone, ammonia, and methanol (and other solvents) will damage PC, gasoline, diesel fuel and turpentine (and more) will damage it. Hence no garages, etc.
I am sorry this turned into such an epistle. I only sat down to write you a few comments. At any rate you have created a very nice website.
Cheers,
Fraser
April 9th, 2007
This is an email inquiry only. Thank you for your website. As others have stated, I’m thankful I’m not being looney about my continuous problems with my new progressive lenses. Actually, I have had three previous pairs of Varilux progressives and have had no problems. Last year, I went back to my same optomotrist and optician I’ve seen for the last twelve years and had three remakes on my lenses and just gave up. I thought I’d try somewhere new this year and upon receving my new glasses a month ago, I’m having the same “swim” issues with the lenses to the point of being nauseous. You wouldn’t happen to be in the southeastern Michigan, northwestern Ohio area to give a recommendation on where to find a good optician?
Thanks much.
April 11th, 2007
I found your site very useful.I was prescribed progressives recently and armed with the information from this site was able
to sort out the problems I was experiencing.They where only minor issues and my optician was very helpful in getting them
resolved.Overall I have been delighted with my progressives,I’d had readers for 3 years and was advised by my optician to
switch to progressives.Reading some of the comments I may have been lucky with my experience of progressives,but I
wouldn’t hesitate recommending them to other people.
April 13th, 2007
Your Site has been helpfull, thanks, I just tried my first pair of Varilux prograssives and was dissapointed in many ways. first in the actually small focal point area, which I have relized is the nature of the progressive glass but also in the markings that they put on the glass, Yes I know your not supposed to see them but I do and believe other people just tolerate them, with todays technologies there is no reason to put them there, with that in mind I’m willing to try another pair of progressive if there is a brand that does not have markings on there lens? in the mean time I’ve returned to my single focus glasses until I find unmarked progressives. any info would be appreciated thanks.
April 13th, 2007
My impression - and I’m definitely not a professional - was that all progressives had the markings. Could your optometrist request some without the markings? Mine don’t bother me, though I agree that progressives have a long way to go before they’re as good as I want them.
I’m wearing the Varilux Physio now, and do like them better than any others I’ve tried, for what that’s worth.
May 17th, 2007
Hello: It has been suggested to me to try and get a no-line occupational progressive lens, when I do get new glasses. I have made an appointment w/eye surgeon office, only because I do not want to use Lens Crafters, Eye Masters, Pearl Vision, so on… I am over 40. I spoke with this office and they were not aware of a no-line occupational progressive lens. They wanted to know what brand of lens they would be. Can you assist?
November 5th, 2007
You say on the Home Page;
Many people find LCDs more comfortable to look at than CRTs. But look out - LCDs have a fixed pixel size. You can’t adjust the resolution to be bigger or smaller like you can with CRTs. So get one with the resolution you like. If you use a CRT, be sure your screen is set to the highest refresh rate - it will be much more comfortable to look at.
Actually, in Windows NT/2000/XP, for instance, you can change the video resolution to whatever the video hardware and
monitor will allow. LCD’s do have a fixed native resolution, i.e. the number of pixels vertical and horizontal across the screen.
If you do not set your display to that exact resolution, E.G. 1024×768, 1400×900, etc., then the image will be interpolated,
and not as clear — but you CAN “adjust the resolution”.
In Windows XP and probably Vista (never used it), in the Control Panel >> Display Properties >> Appearance >> Effects
there is a checkbox for “smooth the edges of screen fonts”. Check the box and pick Clear Type instead of Standard, click
OK, then Apply. If your video resolution is set to the native resolution of the LCD, the improvement and increase in
readability will be huge IMHO. This makes the text on a web page look like a printed page. This feature is why I run
Windows XP instead of 2000.
November 11th, 2007
I am glad or maybe a little disheartened to find others with the same progressive lens problems. I now have struggled for over a year and a half with my first progressive prescription. In the first three months, my Optometrist tried three remakes of lenses finally ending up with Veralux ( I don’t recall what model). They were only marginally better and I have been disappointed struggling though each day. I had never really had trouble wearing glasses with my life long Miopia until Presbyopia set in. I have learned from your site that some of my problem are because of my stylist frames that are only 30mm tall. I also do considerable close-up work over head in the automotive business and cannot see what I am doing. I have sometimes turned my glasses upside down so my close up vision is better while looking up. This isn’t ideal though because of my differing astigmatism between eyes. I will have to resort to numerous types of glasses ( a hassle). This leads to my need for a safety type goggle/glasses with upside down progressive prescription. Does this exist? In my work I have to shift all day long from up-close work to computer screens to driving. Am I asking for the impossible?
December 30th, 2007
Is it just my computer or does the “Vision over 40″ part of your home page partially obscure the text on the right side
of the page so that it impssible to read the text– it cuts it in half-?
Thank you.
Richard Floyd
December 31st, 2007
Hi Richard,
It shouldn’t - can you try a different browser? Do you see a scroll bar, or is the text just truncated? Which browser are you using?
January 9th, 2008
Do all progressive lenses have a small focal point? I just got my first pair of progressive lens glasses
based on the recommendation of my optomitrist. I was told that I would have to turn my head to
focus on objects, but my vision gets blurry at about five inches from center either at computer screen
or reading distance. This does not seem right to me. I was told that I would get used to it, but I
feel this is a little extreme and that it will actually make my eyes worse.
January 11th, 2008
Hi BillyC,
I think they all have a pretty small focal point, but some are noticeably smaller than others. I have Varilox Physio now, and I find them a LOT better than most of the others I’ve tried. From what I’ve read - and I’m not any kind of an expert, just someone who did a lot of research - progressive lenses are an area where the more expensive (premium) ones really are better. If you can, try a premium lens. Online discussion boards might help (there are a few pointers on my Links page), or find a really good optician.
Good luck,
February 4th, 2008
I have been wearing progressive lenses for many years with no problems until now.
I have been wearing progressive lenses for many years with no problems until now. I
am 63 years old, slightly long sighted and unable to read without glasses. My latest progressives
were updated to provide a stronger reading lense. The reading lens is good but
both the mid and particularly long distance are not clear and sharp as in previous
pairs of glasses. In fact I can see into the distance better without my progressives on,
yet my old progressives enhanced the distance. I have been back to the opticians several
times, they have re-tested my eyes, changed the lenses, checked the fitting - but still they
are not right. I am told that I have to get used to them and that some muscle in my eye
has to relax, and they also mentioned something about my eyes over compensating and
it has to get used to the new prescription. I am totally confused - is this a usual kind of
complaint with people of my age? I certainly find the reduction in distance vision disturbing.
The type of lenses I have a VX Ipseo Stylis.
R Sph +0100 Cyl -075 Axis 010 Add 250
L +0150 -100 162 250
(My previous lenses were good apart from the reading)
R -0050 +125 092 225
L -0025 +125 075 225
I am at a total loss of what to do!
Thank you.
Jenny
February 24th, 2008
Hi,
Your website is very informative.
I’ve just spent $600+ on Varilux and the results are horrific - Way too much chromatic aberation.
You’d think an engineer would know all the answers after wearing glasses all his life!!
Anyway - I’m now going to get them changed to a pair specifically for PC work - I do a lot of CAD schematics.
The regular prescription is fine for distance and driving. No way am I considering progressive for driving.
Keep up the good work on your site,
Simon
February 28th, 2008
A few years ago I developed double vision at a distance. If I closed either eye; it went away.
I am diabetic and it was determined that this had caused the problem. At that time the Optomitrist determined that I needed prisms in my lenses. I wore tri-focals then as now.
He also said that in order to utilize the prisms to eliminate the double vision; I needed to go to progressive lenses instead of the normal tri-focals.
The first pair I had worked fairly well; but the newest pair I got have been nothing but problems.
Distance vision has been greatly distorted, intermediate vision is only fair, and reading or computer work is a real pain since there is only a narrow field that allows clear vision.
My question is do I really need progressives or could the prisms still be used with a normal trifocal.
I have repeatedly complained to my Doctor and all they seem to want to do is keep re-adjusting. Personally I feel they errored in making the lenses and don’t want to own up to it.
The lenses were $800 not counting the frames.
Thanks for whatever advice you might have.
March 2nd, 2008
Hi Jim G. and Jenny,
I wish I had some good advice for either of you! This is definitely outside what I’ve learned.
My best idea for both of you would be to try some more informed people, at either: Optiboard Forums or on the sci.med.vision discussion group. Hopefully someone on one of those sites can help.
Good luck with it, and keep fighting to get as much help as you can!
March 15th, 2008
What kind of problem I would face after cataract surgery? I will get -2.5D lens (equivalent IOL) and for reading I will require +2.5D. My job is computer related, but would like to read the manuals without having to change glasses. Ideally PC/Reading glass in one which would not distort my distance vision much. Any comments will be helpful.
Thanks
March 17th, 2008
Hi Sujit,
Sorry - that isn’t something I know about. You might try the Optiboard Forums or the sci.med.vision discussion group.
Best of luck with your surgery,
March 30th, 2008
I just want to thank you for the information. I picked up my first pair of glasses and I thought I was seeing things when I saw the number. The glasses are only 3 days old, so i am going to give them my best to adjust.
April 12th, 2008
I’ve found the hard way that it is possible for the rx in either one or the other lens can be off, which, to the unknowing consumer is not obvious or easy to discern. I’ve also been finding the hard way that when this situation arises that it causes a subtle thrashing and can lead to eye fatigue. The way I stumbled on a way to check this is to close one eye and focus on an object, then close the other eye and compare the sharpness. It now seems obvious to do this check when getting new lenses, but why don’t optometrists mention trying this? Anyone else experienced this “the hard way”?
Just wondered.
Thanks
May 15th, 2008
I was so relieved to find this site and discover that I am not the only one who had problems wearing progressive lenses. Last year, my optometrist suggested trifocals to me. I got them, tried them and just could not wear them. I took them back and got bifocals, which I also had a problem with! He was not very accommodating, and never gave me other options or suggestions. He was the same way with the progressives when I took them back and told him of the “waves”, “prisms” and other major problems I was having, not to mention a profound headache which developed after one hour into wearing them!! He told me I had a problem and there was no more to be done for me except to go back to bifocals–which I did, and I STILL can’t see properly out of these either. I have been wearing bifocals for over 15 years and never had any problems with any glasses I received until I started going to him 2 years ago. So I have come to the conclusion that he is a “bad” optometrist and I won’t be returning. In conclusion, we all know our eyes best and we have to trust our judgement when something isn’t right for us!!! Don’t let any professional blame YOU for their inadequacy!!!
May 29th, 2008
Dear Ellen,
I am stunned to find your site with so many people suffering from their glasses as I did.
The problem with using a computer with progressives glasses is inherent in the nature of progressive glasses. The “clear vision area” is about a third of the width of the monitor. The only non-distorted options are bi-focals or “computer glasses” that give me an undistorted vision bubble that is about 8 feet in diameter.
While I constantly have to switch glasses, it is better than not being able to work at all.
For lack of a better term, I am calling the vision problems caused by my glasses Induced Dyslexia because my inability to comprehend what I was attempting to read was solely caused by my glasses (and the inadvertent ineptitude of my previous optometrist).
I have been in touch with the Ophthalmology Department of Emory University that is interested in doing a study on the problem (typical test subjects being patients over 55 who are having trouble with progressive glasses, usually having to resort to bi-focals or tri-focals) and am now trying to find a way to contact Verilux or one of the other glasses manufacturers that would benefit from the publicity and understanding and would be willing to come up with the $50,000 to $100,000 needed to do the study.
Any suggestions and help would be appreciated.
Allan
allanhytowitz@hotmail.com
http://www.induceddyslexia.com
September 18th, 2008
I have worn glasses since I was 5 years old….and hated it! I’m very farsighted in one eye - and the other is not that great - with severe astigmatism. Never could get any kind of contacts that worked - even the newer ones made especially to correct astigmatism. I’ve needed reading glasses at night, even though I have worn progressives during the day for the last 10 years without difficulty. My night driving vision has been a problem for the last 15 years. Two weeks ago I got my (pricey) Definity/Crizal lenses. When I put them on, I actually started to cry. It was the first time in my life that I could really see everything! I can work at the computer all day without eyestrain. The stairs no longer “wave” as I walk down. My pupils look almost the same size instead of looking “cockeyed” because the left lens always miniaturized my pupil. These lenses are amazing - for me, MIRACULOUS. Now I’m going to give Definity Short lenses a try - and hopefully have some smaller, more fashionable lenses. I know they aren’t available everywhere - but look for them, and save up your $$ and give them a try. Two of my friends have gotten them since I spread the word, and they are as “overjoyed” as I am. Hopefully the price will come down some day and everyone can have them. This is a huge leap for good - no GREAT VISION!
December 28th, 2008
I am a certified Optician in Oregon. All of your concerns pertaining to progressive lenses are concerns I hear often. The most critical element of having succes with your progressive lenses are the measurements taken by your optician for the vertical alignment ( fitting height) and the horizontal measurement ( PD ). The other major element is the frame selection. A frame style that worked for you in the past may not work for you now. Also the more power you need for reading the width of the reading corridor will be smaller. I think another main componet to being succesful with your progressive is the education your optician gives you. You need to know what to expect and what is an unrealistic expectation. I have encountered so many folks that want their eyes to perform like they did when they didn’t need glasses. This is unrealistic. Another thing I see alot is people want one pair of glasses to do it all. Think of your glasses as a tool to help you do your visual tasks. Like with any task you need to use the proper tool to do the job. If you spend a great deal of time reading a book, a pair of single vision readers are going to be more comfortable to use for prolonged periods of reading than a progressive will be. If you spend your eves watching TV relclined in your chair a pair of single vision distance will do the job better. If you are at the computer for long periods of time a variable focous computer lens is going to work better for you. You cannot use one tool to repair your car and sometimes that is true with our vision we cannot use one tool to do it all.
Be sure to tell your optician how you use your eyes. Do you do a lot of close work. A lot of computer work. Active in sports. This is information that can help your optician determine what lenses will work best for you.
Another thing to be aware of is lens material not just lens style. Some materials have much better optics than others.
One thing you should do is ask your Optometrist (OD) or your Opthalmalogist (MD) is their optician is certified and/ or licesned. This will make all the difference. You would be surprised how many Docs do not want to spend the money on hiring a qualified optician. Don’t even get me started on that topic.