Maximum PAL viewing width and adoption?

[DonnaQ]

I'm in opticianry school first semester in Ohio so I'm pretty green. My first glasses were just 12 years ago and I went straight to trifocals as the progressives I tried gave me an immediate headache. Never gave it a serious try which was perhaps the problem, but it seems that technology has also moved on in the intervening decade. So I will have to try again as otherwise my career as an optician would seem limited.

In the meantime, I'm having a useful trial through the eyes of my brother who at 55 just got his first glasses yesterday. Very mild prescription with a 1.75 add, received Essilor poly from Walmart (more for the warranty than anything else). He really likes the progressives in principle, however may have to go to trifocals.

The major complaint is viewing area. He says that only about 40 percent of his laptop width is in focus and described that as only 7-8 words. Books were similarly limited. The second is the funhouse effect and distortion as he moves his head to scan a written line. The soft areas don't bother him so much. One day is not much experience of course, but it is easy for him to get by without using glasses at all, so I think he will not be able to adopt to this version of progressives.

OK, my question is if there are any progressives with effective viewing width similar to standard bifocal/trifocals? I'd love to hear what has worked for opticians here with similar customers. I'm in a tough spot here with my family as I'm expected to be an expert after just a couple weeks of school!

[NCspecs]

Nobody expects you to be an expert, but I would personally expect the ECP who fit your brother to be one. That would include instruction on how a progressive works and what limitations it has. Also, they ought to be able to fit your brother in a lens that best suits his needs based on his lifestyle. This may include multiple pairs. Your brother is not my patient so I will not venture to guess his needs; I will say that I have seen a lot of people who were first considered non-adapts change their perspective of progressives after they were fit properly.

[MasterCrafter]

Digital progressives would be his best bet. No progressive has as much of a viewing area as a lined bifocal. But digital progs widen that up considerably. Also i am not a fan of poly material. It is the worst lens material for clarity. It lets less light into the eye than any of the other lens materials. Try Trivex instead.

He also may be a candidate for 2 sets of glasses. 1 for everyday use. The other he may want to try a Shamir Office lens. Great for computer work and office situations.

[WFruit]

Digital progressives would be his best bet. No progressive has as much of a viewing area as a lined bifocal. But digital progs widen that up considerably. Also i am not a fan of poly material. It is the worst lens material for clarity. It lets less light into the eye than any of the other lens materials. Try Trivex instead.

He also may be a candidate for 2 sets of glasses. 1 for everyday use. The other he may want to try a Shamir Office lens. Great for computer work and office situations.

Free Form progressives are better than Digital ones.... and no, the two terms are not interchangable. I can run a VIP on a digital generator and call it a Digital progressive. Doesn't make it a better lens.

Free Form lenses do have less distortion, both in size and severity compared to conventional molded progressives, but it is not completely elimiated.

I agree that Trivex would be much better than poly, although it's incorrect that it lets less light in (while I generally don't trust wikipedia, see the chart near the bottom of the article for refected light percentages by material http://en.wikipedia.org/wiki/Corrective_lens. Gives you a good understanding of why it's so important to put A/R on higher index materials).

As far as which Free Form brand to use, we run both Seiko and Shamir, with the Seiko being a bit more popular and well liked. I've also heard, though have no first hand experience, that both Hoya's and Zeiss's Free Form lenses are very good.

Having said all that, it sounds like his experience with progressives is fairly typical. Some (most) people get used to, or aren't bothered by, the peripheral blur, some people don't.

[vintagetie]

I work at a practice that frequently uses lenses with awful lens designs (in comparison to many others) when dealing with safety accounts that cover "basic" but not premium progressives. What I have learned is that in addition to a more thorough discussion of needs, a bad PAL can work well as long as the fitting is done with the highest level of skill. Sure, they could do way better in a good lens , but few industrial-setting employees want to chuck out a hundo or two extra for work glasses. Given that he went to a wally world, I assume price may be more important to your bro than quality...

[Robert Martellaro]

I'm in opticianry school first semester in Ohio so I'm pretty green.

Welcome.

My first glasses were just 12 years ago and I went straight to trifocals as the progressives I tried gave me an immediate headache. Never gave it a serious try which was perhaps the problem, but it seems that technology has also moved on in the intervening decade.

Yes, the headache will be less severe with this new technology.:D

So I will have to try again as otherwise my career as an optician would seem limited.

Yes you will.

OK, my question is if there are any progressives with effective viewing width similar to standard bifocal/trifocals?

No.

I'd love to hear what has worked for opticians here with similar customers. I'm in a tough spot here with my family as I'm expected to be an expert after just a couple weeks of school!

Measure the distance to the screen, keyboard, desktop, and any other object that needs to be seen clearly and/or frequently. Note the height of the screen relative to the eyes when the gaze is straight ahead. Confirm that the Add power hasn't been modified (age 55 usually gets +2.00 to +2.25). A simple single vision reader might suffice, or maybe multifocals modified for computer use. Find a local optician that specializes in fitting occupational eyeglasses for presbyopes. Good luck.

[DonnaQ]

Nobody expects you to be an expert, but I would personally expect the ECP who fit your brother to be one.

It certainly would appear that a great optician is more important that a brand. It is daunting to think about the education and experience I will need to come close to being good from my current perspective.

Digital progressives would be his best bet. No progressive has as much of a viewing area as a lined bifocal.

Could you put that in terms of a percentage? For example the widest corridor viewing area is half of the average bifocal? Or 60% more than the Essilor ones he has? That kind of info would help determine if further tries with progressive are warranted for him.

Given that he went to a wally world, I assume price may be more important to your bro than quality...

Actually, he tends to get the best of everything. It just seemed prudent to go to Walmart because of their generous return policy. I took him to my optician, but the return/replacement policy was really bad. Didn't seem like a good idea for his first pair ever. It was my suggestion. And he went with an open mind, i.e. that the first try could work.

Confirm that the Add power hasn't been modified (age 55 usually gets +2.00 to +2.25). A simple single vision reader might suffice, or maybe multifocals modified for computer use. Find a local optician that specializes in fitting occupational eyeglasses for presbyopes. Good luck.

Thanks for the welcome!

As it turns out, the reading lens does not work for computer distance. One other personal characteristic of my brother that will make him hard to fit is that he does not want multiple glasses - just one pair for driving, bicycling, running, computer, and reading. I'm sure I'm going to learn a lot about difficult clients from him!

[uncut]

"....he does not want multiple glasses-just one pair for........"

I see guys like that driving down the highway in their "Swiss Army Knife" SUV, furniture strapped on top, because there is no room inside. Sometime you need a truck.

Hate to break it to you, but....there isn't a lens in the world that will work for your brother, except a contact lens might come close. They have limitations, too.

I'ts my opinion that the Wallyworld generous return/replacement policy is a necessity because of the limited selection/expertise. A really good pair doesn't need a warranty.

If brother really tends to get the best of everything.....were was he when he could have used +o.75, +1.00, +1.25, +1.50 before he needed the now prescribed +1.75 add?

BTW welcome to the Forum, DQ!

[optilady1]

The major complaint is viewing area. He says that only about 40 percent of his laptop width is in focus and described that as only 7-8 words. Books were similarly limited. The second is the funhouse effect and distortion as he moves his head to scan a written line. The soft areas don't bother him so much. One day is not much experience of course, but it is easy for him to get by without using glasses at all, so I think he will not be able to adopt to this version of progressives.


When I explain to a first time progressive wearer what an expected width of the reading area is, I typically tell them about the same as one newspaper column. This gives their brain something to chew on. The funhouse effect (I refer to it as the fishbowl effect) will be so noticeable at first, that the pt's perception of their reading area will be different than what their actual clear reading area is. As their brain adjusts to the progressive, their preceived clear reading area tends to open up. As with driving a car becomes like breathing, his body will begin to align his eyes with the glasses and his surroundings, therefore making him use and wear his progressive correctly, giving him success.

Of course, this all is a moot point if the RX is incorrect.

Tell your bro to of course, give it time, possibly return these and go to a higher end optical shop to be educated on progressives with better technology built in, and above all, if he wants to adapt to them, he will. I would suggest that you have one of your instructers sit with you and explain some lens maps over at thelensguru.com, so you can see the differences between progressives and lined bifocals and trifocals. And good luck to you. I am a graduate of an optical school, and along with real world experience, it can create a rather well rounded optician.

[Robert Martellaro]

As it turns out, the reading lens does not work for computer distance.

No, I can make SV lenses that will provide crystal clear vision for the screen, and might be adequate for the desktop and normal reading. But it's moot because...

One other personal characteristic of my brother that will make him hard to fit is that he does not want multiple glasses - just one pair for driving, bicycling, running, computer, and reading.

There are compromises that can be made that might provide adequate vision and comfort from one pair of glasses, assuming that he doesn't drive a convertible, isn't extremely sensitive to light and glare, and doesn't spend a lot of time, or extended periods of time in front of a monitor.

I'm sure I'm going to learn a lot about difficult clients from him!

The fact that he's family will make it much more interesting. I would strongly recommend that you pass this off to an experienced professional.

[MasterCrafter]

I agree that Trivex would be much better than poly, although it's incorrect that it lets less light in

Totaly wrong about the light. Trivex lets more light in than poly period. Look at this article

"Abbe value is a measure of the dispersion or color distortion of light through a lens into its color elements. Abbe number can also be referred to as v-value. The higher the abbe number, the less dispersion, the lower the number, the more dispersion. Trivex has an abbe number of 43-45. This is significantly higher than polycarbonate. Polycarbonate's abbe number is 30. Trivex has a very high level of light transmittance. The level is 91.4%. This is one of the highest levels of all lens materials. The high percentage is a factor that directly affects the brightness, clarity, and crispness of Trivex."

[WFruit]

Totaly wrong about the light. Trivex lets more light in than poly period. Look at this article

"Abbe value is a measure of the dispersion or color distortion of light through a lens into its color elements. Abbe number can also be referred to as v-value. The higher the abbe number, the less dispersion, the lower the number, the more dispersion. Trivex has an abbe number of 43-45. This is significantly higher than polycarbonate. Polycarbonate's abbe number is 30. Trivex has a very high level of light transmittance. The level is 91.4%. This is one of the highest levels of all lens materials. The high percentage is a factor that directly affects the brightness, clarity, and crispness of Trivex."

First, that's not an article, that's something typed in with quotes....

Second, I didn't say that Trivex lets in less light than poly. I said that it is incorrect to say that poly lets in less light that any other material. Trivex does in fact let in more light than poly, no disagreement there.

Third, what you wrote is about abbe value, which is how much light is dispersed by a lens (whether or not the light is dispersed, it's still transmitted), not how much light is transmitted through a lens. Which is why I referred to the chart that I did, since it shows the perentage of light that each index material does NOT transmit.