I have a pair of glasses that work well for me, that I ordered on-line. I have astigmatism and am sensitive to distortion, but I found that high-index, aspheric lenses with a flat base curve seem to work well. I’d like to find a place locally that can make them for me, ideally with higher quality lenses and coatings than I get online for cheap.
So I went to a local place and spent over $600 on new frames and lenses (this is one pair mind you) and the things came back with terrible distortion when looking off at any angle. I think it must be chromatic abberation since the colors appear to separate. I believe that the prescription itself is correct since I see great looking straight ahead.
So the question is, are there a lot of choices in 1.67 lens material, some better than others? They are both (old = works, new = terrible) 1.67, the same size within 1mm, and same base curve. What can explain this?
The opticians are already giving the impression that they think it’s me and no the glasses, but blurry is blurry. I have a pair that proves it doesn’t have to be that way.
Secondary question, how often are lenses simply bad? I swear just looking at the lenses (holding in my hand) that something isn’t right. Part way from the center it just gets all distorted looking. I’ve never had glasses like that in my life. I even pulled out my box of old ones to check.
I think it is quite common for opticians to screw up in making lenses, and that is probably what has happened in this case. I got a new pair of glasses just a few weeks ago that were made incorrectly. I got replacement lenses (in the same frame) made for no further cost. They made absolutely no fuss or hassle about it. It seems to be a fairly routine thing. Anyway, in most cases most of the cost is in the frames, not the lenses.
Good question. I did bring this up. The long story is that I initially tried these fancy custom lenses called iscription from Zeiss. When they fit those, you stand in front of some camera with a contraption on your glasses and it takes pictures. I couldn’t adapt to the lenses that came back and asked to switch back to my usual thing. They never did anything additional in terms of PD, so it could be way off. I’m not sure how to keep asking the same question in different ways, because I can’t get a straight answer. I think they can measure PD on existing glasses too.
In general I’m frustrated how the business model everywhere seems to be that you do the “better/worse” thing with the doctor, then they dump you up front on some salesman/woman and leave you to try and figure out what frames will work, what lens material, shape, base curve, fit, etc etc. might work. Then they act irritated when it all goes south. Seems like a monkey could do the “better/worse” thing. I need someone with expertise up front.
They do it like that because it’s 2 separate things. The optometrist is doing an eye exam and determining the appropriate correction for each eye, based on what you do and how you do it.
Glasses and contacts are more the actual hardware that accomplishes it.
They do the same thing, mind you, with orthopedic hardware. The orthopedic surgeon does the exam, determines that you need a certain type of knee bracing, and then you go to the brace shop, and they give you some options and make you a knee brace or sell you one off the shelf.
If there are a wide variety of choices in knee braces that lead to widely varying results, this sounds like a mistake too, unless the people at the knee brace place are much more competent than the opticians I typically deal with. Anyone know if there is any educational requirement for opticians, or can you just walk in off the street and go to a three day seminar? I’ve interacted with opticians on-line who seem to really know their stuff, but I assume that’s because they have taken a personal interest. In my experience they mostly just take my money and act grouchy if I come back in with a problem.
There are good and bad opticians. I’ve been going to one for years who delivers excellent quality and service.
There are professionals in any field who are stupid, lazy or selfish. There are bad doctors, bad lawyers and bad engineers. I don’t know that requiring better training for opticians would do much to get rid of the bad ones. They trick is to find one who is smart and conscientious.
I wear glasses (nearsightedness + astigmatism) and once when I was a kid (middle school IIRC) I got a new pair of glasses and it felt like I’d been put inside a fishbowl. Everything was terrible distorted. I said as much immediately when I put them on, got the whole “Oh, pssssh, you’ll get used to them, it’s just a new prescription!” spiel and could barely walk with my mother to the car.
Came back, kicked up more of a fuss (I mean, I’m a kid, but I know FUBAR distorted when I see it even if I’m not allowed to swear yet!) and it turns out they’d put the lenses in upside-down. Which makes a helluva difference when you’ve got astigmatism.
I’m not suggesting additional required training, just observing that some of these people seem like they were working at a fast food joint two days ago.
With this most recent pair of glasses, the first iteration involved them giving me a pair that was a full diopter off in one eye. Of course they told me to give it a week. I could tell by looking at the lens it was off. It’s a knee jerk thing to tell you to wear them for a week to adapt, like IT guys telling you to reboot the computer. Of course, rebooting a computer doesn’t waste a week of your life.
High index lenses are expensive. Wal-Mart sells frames for $10. Of course, good frames, such as titanium are expensive. I, also, paid $600 for high index lenses (break-resistant) with titanium lenses.
I-scription lenses appear to have an Abbe number of 32, which is the same as all the other 1.67 index materials. 32 isn’t good, and you will get chromatic aberration. Short of a super expensive rare earth glass you are not going to do any better (and due to safety and weight issues you don’t get glasses made of this anyway.) I-scription seems to also be more than just the material, but covers the lens profile as well. They can be of a free form shape optimised to provide less image distortion than a simple cylindrical or spherical shape. But of course this means you are not comparing like with like with the different lenses. Your cheap internet lenses are probably a simpler profile, but it turns out one you like. The Zeis profile might be more sophisticated, but for your particular needs and preferences, less suited. Some people seems to find chromatic aberration more disturbing than others, although no matter what, it leads to some blurring.
I am about a dioptre astigmatic in one eye, and use Trivex reading glasses. These have an Abbe number of 44, which is much better. But one dioptre is a trivial amount of correction, so I get away with thin lenses in a material of index 1.53. I get absolutely no discernible chromatic aberration. Clearly a stronger prescription makes life harder on every front. Once you are forced into higher index materials everything will be about compromise.
If you can manage to drop to an index of 1.6 you get to Abbe numbers of about 42, this could make a huge difference in chromatic aberration.
In theory, the prescription takes care of the actual clinical part- it’s the proper correction, or specifies the axes the brace is to limit motion, etc… but there are options beyond that which are more or less out of the purview of the optometrist/orthopedic surgeon.
For example, I may want impact resistant lenses- that’s none of the optometrist’s business or concern, as long as the opticians grind the lenses and fit them to the frames appropriately. Or, based on the degree of instability and prescription, I may not need a custom fitted brace, but can get away with an off-the-shelf one. Or I may want a blue one, or red one.
That’s why the separate it- you may want Kenneth Cole frames and anti-reflective coated lenses, and in glass, not plastic. Making all that work in your prescription is the optician’s job, not the optometrist. The optometrist just determines that your eyes are -2.00 diopters, etc… and tells the optician via the prescription.
Thanks for the reply. I started with Iscription and couldn’t adapt, so now I have plain 1.67 aspherics. To be clear here though, the Iscription had none of the blur or abberation, they just gave me a weird dizzy/pulling/swimming sensation that I couldn’t get past. They were clear edge to edge. So if Iscription are low Abbe, this is another data point saying that these glasses simply have a problem. And just to be clear, this is no subtle effect of chromatic aberration. I’m talking about looking at a car straight on, then turning my head 45 degrees and the car is twice as long and the colors are separated. I can’t believe anyone would tolerate this.
One other thing, the frame can affect how well the lens works, because the frame design determines the positioning and angle of the lens. One time I had new glasses that appeared to have a lot of distortion, to the point of making me feel dizzy. The prescription had changed very little so I knew something was wrong. It turned out the new frame positioned the lens much further from my eyes, and angled further inwards. I went and found another frame that was more similar to my old one, and that fixed it.
I’m assuming the “distortion” is large scale, not small scale wavynes? That could be caused by heat damage to the lens. I’ve had that happen too - the tech used a heat gun to adjust the frame and evidently pointed the heat gun directly at the lens at some point.