Eyeglass question (bifocals)

[Coytee]

(Maynard?..... sounds like you might have some background in this area)

Here's a general question that I don't expect anyone to really know... (asking since I'm relatively new to glasses)

I got a new pair of glasses, I opted for the lined bifocals.... wore them 2-4 times over 48 hours and frankly, they drove me nuts. No problem...I'll go back and fork out difference for progressive (happily I might add)

Progressives are now maybe a week old. From the moment I put them on, I had more of a sensation (than an abilty to articulate a specific cause/effect) that there was something different about them.

Example: I find it easier to take them off at work, put on my (something like +1.5) reading glasses, look OVER the readers for PC work and look through them for reading/writing. This same reality happened with my first pair of progressives but, I never felt the need to swap to the readers. Maybe I should word that differently.... the first pair of glasses, though being imperfect at both tasks, executed both tasks (PC and reading) better than the newer glasses.

Long story cut down... I got to experimenting... closed right eye looked at something with left eye through the top of the new glasses. It was blurry. I then scanned down with the left eye to find the area of the glasses where the left image sharpened up. For arguments sake, let's say it was 25% up from the bottom of the lens. I then closed left eye, opened right eye (in my very scientific way!) and repeated.

What I noticed with the right eye is when I was at that '25% up from the bottom of the lens' area, the image was still out of focus. It really wasn't until the eye was looking at the lowest EDGE of the lens (which was very difficult to do) that the image sharpened up like the left eye.

In short, it almost seems as though the focus of the right lens is shifted a bit and needs to be raised.

I bought the Nikon lens "these are computer ground". I recall there were three choices and memory says I took the second choice which allowed a wider focus of field.

Frankly, it seems as though I'm looking through a camera lens where the focus ring is just a notch or two off from being laser perfect, making the sight a bit fuzzy BUT, "livable"

I'm planning on going back to have this conversation with them.

Any thoughts?

[tube fanatic]

(Maynard?..... sounds like you might have some background in this area)

Long story cut down... I got to experimenting... closed right eye looked at something with left eye through the top of the new glasses. It was blurry. I then scanned down with the left eye to find the area of the glasses where the left image sharpened up. For arguments sake, let's say it was 25% up from the bottom of the lens. I then closed left eye, opened right eye (in my very scientific way!) and repeated.

What I noticed with the right eye is when I was at that '25% up from the bottom of the lens' area, the image was still out of focus. It really wasn't until the eye was looking at the lowest EDGE of the lens (which was very difficult to do) that the image sharpened up like the left eye.

In short, it almost seems as though the focus of the right lens is shifted a bit and needs to be raised.

You raised an issue that is very common, unfortunately. For a progressive lens to work correctly, the optical centering relative to your pupils has to be near perfect. A misalignment of even 1mm can throw the teaming of the eyes out the window! There are 2 possibilities here: 1) your refraction was not done correctly so that the RX generated is not correct, or 2) the optical centering of one or both lenses is not what it should be. When taking measurements for progressives, a device called a pupillometer should have been used (kind of looks like a pair of binoculars with you looking into one end while the doc or optician looks into the other) to determine the horizontal optical centering of each pupil relative to the bridge of your nose. Vertical measurements must be measured separately for each eye as well- often this is done with a plastic "scale" inserted into the frame and marked in millimeters, or by simply putting a little dot corresponding to your pupil location on the frame's "demo" lenses with a Sharpie pen or equivalent. Then, the vertical measurement can be taken. Obviously, given everyone's facial asymmetry, it's rare that the centering will be the same for both eyes. Other critical factors are whether the frame was sitting perfectly horizontally on your face, and whether it was sitting on the bridge of your nose in the exact place where you intend to wear it. Many opticians or docs place the frame where it "should" sit, which is rarely where a person prefers it. So, going back is absolutely essential. I'd insist on having the refraction remeasured, and if it comes out the same, having them remeasure the optical centering and make you new lenses (again- you place the frame where you intend to wear it, and also position your head as you normally hold it. Some people sit or walk around with their chin slightly lowered or elevated. If measurements are taken with your head perfectly erect, the lenses won't be correctly centered in your normal circumstances.) Even if they tell you that all is perfect, I'd demand new lenses as they can have all kinds of distortions which may not be readily measured. One last issue is the vertical size of the frame. Current styles tend to be very small vertically, often no more than 30 or 31mm, and sometimes less. Although there are progressives out there which are supposedly designed for that application, it results in severe crowding of the zones and can cause difficulty in selecting just the right spot for a particular viewing distance. My recommendation is to choose a frame with a minimum vertical height of around 37mm. The difference in lens performance can be profound. So, once all of this is done, you will be able to make a proper assessment of how progressives work in your situation. Maynard

[Coytee]

Ok, well you dropped a load of info!

I tend to wear the glasses tight/high (not sure what the right word is) but... "close to my eyes and not down on the nose"

At the risk of a bit of embarassment....this tends to conflict with my eyelashes which then lightly brush the lens so I fidget them about to find that happy spot. I WANT them tight (which flutters with my lashes) but sometimes wear them a slight further down to eliminate the flutter.

Possible issue: My eye-doc (Opthamalogist) is in Tennessee and I got the prescription through his office when I went home for a visit. I then took it to Walmart here in Florida for filling.

I HAVE debated the merits of simply having another eye examination done, regardless of insurance coverage however.... if his diagnosis is off a bit then it's not the fault of Walmart.

The lens themselves are roughly 31 / 32 mm, about 1 5/8" in height (edge to edge). Sort of the square 'avaiator' type look. I usually have (sun) glasses sit high on my nose which means they tend to cover half my eyebrows. I guess I don't have a face that is a natural for all the cool frames. Regardless, one reason I went with this was specifically having more real estate for the lens and hopefully, a larger focus section for each half.

The prior pair which seem to have a better net focus for me, are NOT as high as these are.

I'm absolutely sold on the progressive lens so I don't have any issues there. The experiment with the lined bifocals kept me aware of the fact of looking through them rather than simply looking through them.

The more I think about this the more I realize I need to at least have a conversation with them and.... be open to the idea of simply redoing an eye exam.

It's certainly possible that a mistake was made at my Dr's office. I guess it's equally possible that a number was transposed and these might be off by a fraction. So, figuring out what the underlying issue is would be the first challenge.

[dtel]

So, figuring out what the underlying issue is would be the first challenge.

Old age [8-|] But your looking really good Coytee, considering your age, really you look days younger than what you really are. []

But your not alone after reading this, I could only read it because of glasses.

[tube fanatic]

The more I think about this the more I realize I need to at least have a conversation with them and.... be open to the idea of simply redoing an eye exam.

It's certainly possible that a mistake was made at my Dr's office. I guess it's equally possible that a number was transposed and these might be off by a fraction. So, figuring out what the underlying issue is would be the first challenge.

One last suggestion if you choose to have another exam. Ask the doc to put the measured near vision RX into a trial frame. This is the "old fashioned", huge clunky affair into which individual lenses can be placed to create any prescription. Once that's set up, verify that both eyes achieve maximum clarity at the same distance from your face by testing them alternately, and asking that they measure the distance for verification. There are times when a slightly asymmetrical reading RX is required to balance the focus. It takes only a minute or two and is worthwhile. Regarding your lashes hitting the back surface of the lenses when they're all the way up, if you happen to be using a metal frame with adjustable nose pads the fix is simple. The pads can be adjusted so that the frames are sitting just far enough in front of your face to prevent the rubbing. The frames can still be made to fit quite snugly. One last alternative, available for some frames, is to have them change the temples to the cable variety (the type which curls around the entire ear from top to bottom.) That will certainly keep them just where you desire. Good luck! Maynard

[Coytee]

Regarding your lashes hitting the back surface of the lenses when they're all the way up, if you happen to be using a metal frame with adjustable nose pads the fix is simple. The pads can be adjusted so that the frames are sitting just far enough in front of your face to prevent the rubbing

and I thought you were going to suggest I simply trim my eyelashes back....

[]

[tube fanatic]

and I thought you were going to suggest I simply trim my eyelashes back....

Of course, that's always an option!!! Then, there's an eyelash curler......... But look at the positive side- if you were a woman you would be dealing with mascara streaks on the back of the lenses instead of just some oil.

[Coytee]

Went to the store yesterday & went over the situation. They seem nice & open enough.

I said I'd like to have an exam done by them, even if it's my own expense ($55 which I'm going to happily pay)

Said I just want to hit the reset button and review all stages from the beginning to find out if it's their mistake or the original prescription.

Oh.... get this (forget if I've mentioned this or not)

I was going to order a pair online and discovered you need this PD number. No biggie....until I found out that nobody will give it to you. Ok, so I decide to forget that idea HOWEVER, being the curious type, I was wondering what it was.

When I first went for the new pair of glasses, I looked at the paper she wrote on after I looked through those 'binocular' things for them. Her values were 32, 65 and 33. I don't know what all this means so I'm presuming it means my right eye is 32 mm away from the center of my nose, left eye is 33mm's and the 65 is a check digit?

Regardless of what the numbers mean, I also peeked the second time I went back and ordered my current version. Those numbers are 29.5, 59.5 and 30.5. What the heck???

Why so different?

In fairness to them, it's certainly possible that I misunderstood what I was seeing or perhaps looked at the wrong number. I don't think I did since the numbers were viewed by me (backwards from across the desk) just after they wrote them down. To have the wrong numbers would imply that they took my measurements and wrote something different than what they saw....perhaps in code or something. Meaning, I saw the numbers & wrote them down as I was sitting there.

Strikes me as strange.

[tube fanatic]

When I first went for the new pair of glasses, I looked at the paper she wrote on after I looked through those 'binocular' things for them. Her values were 32, 65 and 33. I don't know what all this means so I'm presuming it means my right eye is 32 mm away from the center of my nose, left eye is 33mm's and the 65 is a check digit?

Regardless of what the numbers mean, I also peeked the second time I went back and ordered my current version. Those numbers are 29.5, 59.5 and 30.5. What the heck???

Why so different?

In fairness to them, it's certainly possible that I misunderstood what I was seeing or perhaps looked at the wrong number. I don't think I did since the numbers were viewed by me (backwards from across the desk) just after they wrote them down. To have the wrong numbers would imply that they took my measurements and wrote something different than what they saw....perhaps in code or something. Meaning, I saw the numbers & wrote them down as I was sitting there.

Strikes me as strange.

Your presumption about the numbers seems correct. The sum of the monocular PDs (stands for pupillary distance) should be what you stated in the first case. Why there was such a big difference when it was remeasured is a bit of a mystery, as is the 59.5 which is .5mm less than the sum of the individual measurements. Was it an optician who did the measuring, or just a "frame stylist?" I should have suggested that you insist on the optician taking all the measurements. I guess the proof is going to be in the final result. If you get the new glasses and all seems well, I wouldn't be concerned. What about the RX itself? Was is very different from what your ophthalmologist measured? The issue of providing people with their PD has been raging for some time. In an effort to prevent folks from purchasing glasses online, some docs refuse to provide that information. That's pretty sad. Others make patients sign a statement saying that they won't be responsible for improperly made glasses and that there will be a charge if they recheck your RX and find that the problem was a fabrication error. There's a lot of "attitude" in the eyecare field and always has been. Forty or so years ago, some docs even charged patients for their RX if they didn't want to purchase their glasses from them. As if that was going to create the goodwill needed to retain them as patients! So, when the new glasses come in, please post with your impressions.

Maynard

[Daddy Dee]

OK. Went in for eye exam last week and new glasses this week.

Asked the doc about the difference between no line bifocals and old school bifocals.

He said that no line bifocals have a much smaller (sweet spot - my words) to look through. ie. wearing them requires the wearer to point his nose at whatever he wants to see.

this is certainly confirmed in my experience with no line bifocals over the last several years. Some years back i reported trouble to the doc when i first started wearing them. I had been accustomed to just looking in different directions with my eyes. it took some adjusting to go to bifocals because of needing to point my nose at whatever.

Further, he said the old school bifocals have a much larger space to look through. There is just no transition from one magnification to the next.

I filled the Rx with no line bifocals on the regular glasses. Am using the old school bifocals on sunglasses. First time ever with the old school bifocals and it's an interesting contrast. One of the selling points on the no line bifocals is that computer users often like them, because with screen can be viewed with through the transitional part of the lens. Sat in the car for a while today and used the sunglasses bifocals to do a bit of reading. It is sort of amazing how much more lens area there is to see through. That will work fine for sunglasses. Think i use the transitional capability of the no line bifocals more than i had realized.

[CECAA850]

Excellent review. It gives me food for thought as I may be traveling down that path sooner than I'd care to think about. I had perfect vision till I hit 50 and ever since then, I've had to use cheaters for reading. I have always been able to see exceptionally well far off but I can tell now that even my far vision is getting a little fuzzy as of late.

[tube fanatic]

I was surprised to see this topic resurrected! DD, as you found out, different lens options are optimized for different applications. With the progressive multifocal lenses, most people don't realize just how much they are using the intermediate focusing ability for many things (the computer screen being only one.) And as you noted, the "sweet spot" (a wonderful analogy!) can be quite small. If you decide to purchase others in the future, talk to the optician or doc about the progressive lenses from different manufacturers. Some have a wider corridor for the intermediate range. The advantage of those is that when viewing a computer screen, for example, less of a head movement is required to maintain clear focus. There are so many lens options out there that something is available for any application (even bifocals with the near segment on top and bottom, with the distance portion in the middle- very useful for painters and mechanics who often have to work above their heads but need to have a clear near focus.) Enjoy the new glasses! Maynard

[Daddy Dee]

Maynard, thanks. good to know about what different manufacturers might provide.

[Mongo171]

I knew I needed to get a new prescription for glasses once I got my new TV. 1080p just wasn't that sharp. Then, I realized it was my glasses. Yes, I go for the old school lined bifocals.

[Coytee]

BAH!!! ya bunch of old men!!

[*-)] [:#] [*-)]

[Daddy Dee]

You forgot "grumpy"! []

[Daddy Dee]

You forgot "grumpy"! []

[Daddy Dee]

One more thing about bifocals. I've been wearing them 20 years or so and have always used the no line variety. It had been a point of minor frustration that all these years i've taken the glasses OFF to read. Seemed silly to spend the extra bucks on bifocals if i wasn't useing them to read. Always could see the book page better without them.

OK, so last time i got a new rx was not quite two years ago. Told the eye doc i wasn't planning to NOT fill the bifocal part since i wasn't using them to read. She said, do what you want, but you might be surprised how much you do use them.

Got the glasses, just the near-sighted correction and was indeed surprised how much i had used the no line bifocal correction without realizing it. Glasses w/o bifocals for me then required taking off the glasses to read a label in the grocery store and many more situations that i hadn't realized when the lenses had been helpful after all.

This time doc was kind enough not to say i told you so.