Progressive Ink Markings on Uncuts - not always provided??

[ndolbee]

Hello, first post here.

So I recently started in an office that gets all of its progressive lenses from VSPOne Dallas (formerly Legends). I was able to spend some time with the office's finishing lab tech and he showed me that VSP One will frequently not provide the typical progressive ink markings. His feeling was that its something they are leaving off when they are busy. When the regular markings are absent they provide the outer two dots which he uses to line up on the progressive marking pattern and he draws them out before he moves on to blocking the lens. He tells me it has been this way for over a year, but no one has looked into it.

To be completely clear, I am not referring to the laser etched progressive identifiers.

So is this typical from a lab? I'd have expected the markings to be provided every time. We are trying to decide if we will be staying with this lab or not, going forward.

Thanks in advance

[WFruit]

Depending on the lens, a lot of the time the markings come off during processing in the lab, as well as cleaning.

However, there are lens printers that will put the marking back on, or at least generic markings, such as the 180 line, PRP, fitting cross and distance circle. They could also provide the manufacturer's verification masks to put on the lens (or put them on themselves, although they don't always cling to A/R real well).

You should always get some kind of markings in my opinion. And yes, I work in a lab. And yes, we have a lens printer.

[golfnut]

We get the two outer markings quite often. My biggest problem with that is they are often not even close and then how are they checking pd's and seg ht's?? Just a pet peeve I guess?

[ml43]

We get the two outer markings quite often. My biggest problem with that is they are often not even close and then how are they checking pd's and seg ht's?? Just a pet peeve I guess?

Ink PAL markings are normally only used for surface blocking, and are removed prior to hard/anti-reflective coating.

It helps with inspection of the lens before it is passed on to the finish side, and all ink must be removed prior to dip coating, AR coating, and hydrophobic coating.

When it is passed on to the finish side, the person doing the initial inspection and/or blocking will redraw the markings.

After edging, all ink marks must/should be removed again before final inspection.

The dots you are seeing are likely just being put there as either a courtesy, or by the final inspector as a final check to make sure the PAL seg dots are parallel.

Hope that answers your question

[golfnut]

We get the two outer markings quite often. My biggest problem with that is they are often not even close and then how are they checking pd's and seg ht's?? Just a pet peeve I guess?

Ink PAL markings are normally only used for surface blocking, and are removed prior to hard/anti-reflective coating.

It helps with inspection of the lens before it is passed on to the finish side, and all ink must be removed prior to dip coating, AR coating, and hydrophobic coating.

When it is passed on to the finish side, the person doing the initial inspection and/or blocking will redraw the markings.

After edging, all ink marks must/should be removed again before final inspection.

The dots you are seeing are likely just being put there as either a courtesy, or by the final inspector as a final check to make sure the PAL seg dots are parallel.

Hope that answers your question

The markings are needed for final inspection if they are indeed checking pd, seg ht, prism, axis?? There is no way the inspector can know these things without the markings though.. I guess as I sit here and think about it, they could have been marked for inspection and then cleaned completely off then they reapply the markings haphazardly just for my benefit??

[ml43]

The markings are needed for final inspection if they are indeed checking pd, seg ht, prism, axis?? There is no way the inspector can know these things without the markings though.. I guess as I sit here and think about it, they could have been marked for inspection and then cleaned completely off then they reapply the markings haphazardly just for my benefit??

Of the three labs I've worked in, final inspection is done with a digital LM.

seg dots are only drawn as I stated, to make sure they are parallel and to the specified height.


PD should be good, as most use auto blockers, and it is normally the most experienced person doing the initial inspection and blocking.


When I first started in lab, I would only leave the fitting cross and nothing else.
but it can take a toll on your eyes when you are doing it 100 times a day.

[golfnut]

I guess I wasn't considering automated machines checking pd and seg placement at final inspection?? As far as trusting the layout person, anyone can make a mistake no matter how experienced. I will say that the quality of the work I receive from my labs is really really good though. I worked in wholesale labs 10 years ago and did final inspection as well and I am sure things are completely different today!

[WFruit]

If a human being is doing the checking, with a manual or digital lensometer, the markings should be there ON UNCUTS. If it's just stick the lens in a machine and have it do the reading (usually by mapping out the lens), then the lens should be clean at Final.

On a completed pair of glasses, there should be dots and the fitting cross at final. For how the lenses leave the lab, that's up to the account. We have some that want them completely clean, some with just the engravings dotted, some want the entire set of markings put back on. That applies to both uncuts and edged work.

[ndolbee]

If a human being is doing the checking, with a manual or digital lensometer, the markings should be there ON UNCUTS. If it's just stick the lens in a machine and have it do the reading (usually by mapping out the lens), then the lens should be clean at Final.

On a completed pair of glasses, there should be dots and the fitting cross at final. For how the lenses leave the lab, that's up to the account. We have some that want them completely clean, some with just the engravings dotted, some want the entire set of markings put back on. That applies to both uncuts and edged work.

Thanks for the information! This is what I was hoping to find out. Meeting with the lab rep tomorrow so this is very helpful.

[ml43]

If a human being is doing the checking, with a manual or digital lensometer, the markings should be there ON UNCUTS. If it's just stick the lens in a machine and have it do the reading (usually by mapping out the lens), then the lens should be clean at Final.

On a completed pair of glasses, there should be dots and the fitting cross at final. For how the lenses leave the lab, that's up to the account. We have some that want them completely clean, some with just the engravings dotted, some want the entire set of markings put back on. That applies to both uncuts and edged work.

Good points, forgot to ask if we are talking about edged jobs or uncuts.

For uncuts, a lot of labs will leave the seg dots, along with underlining the add power. (this is how all jobs leave eyemed labs)

For newer digital lensmeters(that don't fully map the lens), you dont need the fitting cross.

Just the seg dots, to make sure you have the lens in the right orientation, and so you know your reference point for axis.

Ideally you do want everything drawn, but that is just more work. And if we are talking about uncuts, the person edging the job should be redrawing it.