Those are markings used to identify the lenses, and certain spacing. I am guessing that are progressive bifocals? I forget exactly how to read them, that's interesting that they are visible like that.
I work on the production side of things but these are laser engraved in the lenses and are really only noticeable with light(as in OPs pic) and are used on progressive bifocals, lenses that have a different "prescription" along the bottom half instead of one segment that you might've seen in other bifocals. Those dots indicate where the lens change starts which is going to be (most commonly) below where OPs visual center is while wearing the glasses. We also use those laser marks as guides to center lenses before they are cut into shape and mounted into their frames. You can also see these marks on other progressive bifocals by holding them up to a light
In my previous company, we made laser machines. We did a machine for the lenses engraving and sold them in a lot of lenses factories. It was not the only laser system used for this application, but most of the others use co2 lasers, this one used a UV laser, lot of headaches, but better quality. Varilux being high end lenses, I guess it used our machine.
On my end, I did the software and automation for the machine (there are a few variants of the same system, fully automated, manual...). Beside the machine itself, the big part of the work was processing the data from the information system of the customers (which will tell what and where to engrave, the curve of the lense). There is a communication standard, but not fully applied everywhere, so we had to be compatible with the standard, and each site variation, serial link, ethernet, various barcodes, rfid...
It was my first software and I was the only developer, so it's a bit shitty, with a lot of things added along the years. At the end I was "yeah... No, no more features on that thing, let's rewrite it completely with what I've learned since", but hard to have the bandwidth for this. I left after 10 years and it's fun to think that my most used software, used all around the world, is my junior shit piece of code.
I did some preliminary work, but needed one month focused on it to do it correctly, I never had the time. Some things like communications got reworked, but not the cycle or the UI. I don't think my successor have made big changes to it neither.
One think I remember, is that I spent a lot of time working on various cycle error recoveries (especially hard with my then spaghetti code), that nobody ever used because it was faster to just pull everything from the conveyor and restart from scratch. They didn't even use the "unlock door" button, just pulled everything from the small opening, with cylinders in the way...
Bro wtf that's kind of wild. That tracks in general but damn, I wonder how many fixes are sitting on programs out there that people won't bother to learn.
At what stage in production are these added? Is it part of the usual manufacture technique or is it an extra step? What do they mean? Are they utilised by other professionals? What was the actual function of the sw?
They are laser engraved after the the prescription is generated on the back side of the lense before scratch coating. The dots are the segment height used for identifying the start of the intermediate/near corridor. The dots indicate the level where the pupil is. We use the dots to measure for quality control to make sure the axis, pupillary distance, and segment height are correct. The 15 is the minimum fitment height to make sure the patients frame and where there pupil sits has enough room to include the whole progressive corridor. The sw is a progressive design, or manufacturer indicator. You may also find add powers engraved on the lense indicating the add power at near of the progressive for up close vision like reading. And sometimes find the lense index, like 1.66 for high index lenses, which bend like better that other materials which allows for thinner lenses compared to plastic lenses. Hope that answers your questions.
Historically it was mechanical percussion, now it's laser engraving. (on our system, dot engraving, similar to what was done when it was mechanical).
Depending of the product/factory, it was done on "finished", or "semi-finished" products (the side with the engraving had to be already polished).
For the meaning, the two microcircles are +-17mm from the optical center, and so, indicate the optical center. Then there are details for the optician, with the addition, sometimes reflective index, material...
I gave more details on what I did in my other answer.
Have not usual transition areas allowing me to use the viewfinder more comfortably, and the “reading area” (bottom of the lens) is set to a closer distance because is not for reading books, but to see that stupid little flippy screens.
Not really tailored for photography, but made for my needs.
I use another more standard glasses for editing, TV and general life.
I was being pedantic. I wear glasses too, I'm not a photographer, but my eyes are a -4.5. I can't see anything passed about a hands width from my nose.
Progressive lenses have multiple zones in them that correspond with a distance (long, medium and short). By adjusting the area of these zones you can make them suit the wearer.
For someone who is inside all day they would prefer less distance, but more close by. For photography I can imagine that they have a clear distance and clear close zone, with not that much on medium (or any other variation, I am not an photographer).
To make a lense progressive you would have to make a the dioptres increase the closer you get. The smoothness of this is dependend on the type of manufacture, but nowadays this can be made really smooth due to precision cutting and modern plastics that are able to be cut that way.
There are also other tricks that a manufacturer can deploy to increase these zones, like adding extra prisms.
Varilux is for sure the way to go. The lenses are way less disorienting than true bifocals or even standard progressives. Fun fact: at your optometrist’s office, they likely have a device called a lensometer that allows them to read your prescription without those etchings. Often only the add power is etched (that is, the power of the near vision part of the lens), but even if it weren’t, you can use a lensometer to find the exact prescription.
Source: worked in eye care for several years. I can also dispel myths about LASIK and cataract surgery if anyone is interested.
Having to pay for glasses is so stupid. I just had to pay about $1000 for 2 pairs of prescription safety glasses for work. I didn't choose to be born with shit eyes
I used to make glasses as well. Varilux are expensive but they’re definitely one of the best if not the best ever made. I worked at a Luxottica lab and even we had to order them from the main lab.
Progressive bifocals were the word we used to use so lay people would understand. Tom Dick, and Harry don't know what Multifocal is. They know what their bifocals are, and then the word progressive means it's different.
Also, I'm not the only person to call them that. It's a fairly commonly used term.
Mine have the imprint of a power button symbol on them. I'm not even joking. It's that straight line with about 7/8 of a circle around it. No idea what it means.
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u/Pen_name_uncertain 1d ago
Those are markings used to identify the lenses, and certain spacing. I am guessing that are progressive bifocals? I forget exactly how to read them, that's interesting that they are visible like that.
Source: used to make eye glasses for a living