- I don't know about you, but me,
I can't bear another second without part two
of Verification, Final Inspection!
(cheerful upbeat music)
(inspiring upbeat music)
Good morning!
Yes, I know, it might not be morning where you are,
but every once in a while I get to say that.
I would like to welcome you
to the Laramy-K OpticianWorks training center
where we are gonna pick up
right where we left off last week, and jump into part two
of Verification and Final Inspection.
I said we were gonna pick up right where we left off,
and that is exactly what we are going to do.
Couple things to mention again.
Verification/final inspection
should be a quick double-check
of what's coming back from the lab.
Now, last week I talked about
that you really don't have a lot of control
over some of the, well, garbage that comes back
from some of the vision care plan labs.
You have complete control over the quality of the work
that comes back from the lab
that you actually do business with.
One-to-one, you buy from them
and sell directly to your own customers.
If they keep sending you garbage
and you have a constant struggle
with verification/final inspection, find another lab!
May I suggest Laramy-K?
Remember that verification/final inspection
is of both the frame and the lenses.
90% of your customers really don't care about the lenses
at all unless they have some giant scratch on them
or they can't see through them.
They're really concerned about the frames.
So start with your frame,
be picky about those maybe a little bit more
than about lenses.
Shorts, shoes, and glasses.
If I go downtown later this afternoon,
I buy I pair of shorts and I bring 'em home,
and I put them on and they fall down around my ankles,
I don't wear the shorts.
I bring them back and I get a size smaller.
If I go online and I buy a pair of shoes
and I get them home, I put them on
and they killing my feet, I mean, painful, horrible,
they feel like they're two sizes too small,
I don't wear the shoes!
I send them back and I get two sizes up.
If I go downtown or I go online and I buy glasses
and I get them and they don't work, I send them back,
I don't wear them.
Look, no one is going to die here
when we're talking about applying
these standards and tolerances.
Well what if I fill a expired prescription
and somebody drives and gets into an,
it just, nobody is gonna die here, okay?
Get over that nonsense!
You're not helping our profession.
Why do we have standards?
Why do we have ANSI?
Why do we bother to check?
So that you get what you paid for,
lab bills are expensive.
If you order a minus seven, you wanna make sure
you get a minus seven, plus or minus the tolerance
that is allowed in the industry.
Hence you pass that on and make sure that your customer
gets what they paid for.
Really important, right?
They did the refraction,
they said number two is better, that was a minus 6.50,
make sure they get a minus 6.50.
The real reason, why do we have industry standards?
To cover your ass.
Redos.
New customer, they put on the glasses,
they say, "These don't work.
"Oh God, no", and they're taking the new pair off
and putting the old ones on and back.
Well now my old ones are better.
You're like, "Oh, no, this is not good."
They're gonna have to go back to their doctor,
and you wanna make damn sure that what you dispensed
meets the industry standards.
Even if that means compensated lens design,
which most people don't even understand.
So you might wanna check that video out.
Touching on this, we got two more words to cover,
and then we'll get to the math.
There are two terms that we absolutely,
positively must understand before we talk
about applying tolerances, applying the math of tolerance
to an eyeglass lens.
One of them is subjective.
Subjective means that something is open
to the interpretation of a human.
Feelings, thoughts, beliefs.
Things like religion and politics, eyeglass prescriptions.
Open to human interpretation or perception.
Refraction, which is better, one or two,
is a subjective measure.
Really, really important.
Lenses, as worn by a human being, are subjective.
They are open to human perception.
Remember, focal length change, vertex.
We've all heard the story of the crazy lady
who swears she's completely blind
without her mins .500U glasses.
Lenses, as worn by a human, are subjective.
Super important thing to keep in mind
before you go applying standards as some kind of law.
A manual lensmeter,
the moment you put a human in front of it,
becomes a subjective tool.
If you're young, you can accommodate and you sit there
and you rock that power drum back and forth,
God only knows where you're gonna end up.
Subjective.
Objective means that we have completely removed
or done every possible thing to put a check
on the human interpretation of a finding.
Well-calibrated, well-maintained,
electronic measuring tools are objective measures.
A properly maintained and well-calibrated
auto lensmeter, a dual lens mapper,
an electronic measuring device.
Those are objective.
It takes out the human element.
Manual tools, how we got along for thousands of years,
a properly calibrated set of calipers,
perfectly good objective tool.
For goodness sakes, a ruler, a PD stick, it's a good one,
an objective tool.
Lenses.
Lenses are objective.
We've got all that great math and science
that we can prove exactly what a lens does
and how light moves and its focal length.
It's objective, it's a beautiful thing.
The minute we take that objective lens
and place it on a human being, it becomes subjective.
So just remember, remember our scale,
we're weighing out our customer satisfaction
versus the interpretation of these tolerances
that we're talking about.
You have to balance those things.
There is a difference between an aircraft mechanic
and an optician.
Aircraft mechanic, she works on the Boeing 737 engines.
If she messes up, 350 people will die.
She is measuring an objective item,
let's say it's an O-ring, against an objective standard,
give or take so much tolerance on either side,
and placing it back into an objective tool or an engine.
That's very different, and there's a lot weighing
on her decision-making.
An optician is taking an objective tool, a lens,
putting it against, hopefully an objective measure
of when we're talking about tolerance,
but subjective by its creation because a human chose
the power that the lens is.
And then we're gonna turn around
and we're going to put it back on a human,
making it further subjective.
I really need you to stop for a second.
This is really, really important for you to understand.
There is a difference between these two things.
There is a difference between a subjective
and an objective measurement.
And just please, just never forget
that we're talking about something
that we are placing on humans,
and humans have different perceptions.
Let's take a look of two examples
of how we actually apply tolerance.
Now the first thing, if we're working with something
intricate enough that it requires tolerance,
we wanna make sure that we're applying it the correct way.
So find your chart, whatever that might be,
and just look at it.
Read your columns, read your rows,
look for any notes at the bottom.
Make sure you understand exactly which tolerance
you're applying and why
before you go making any judgment calls.
All right, I'm gonna run through two case examples.
This is our first one.
You ordered plus 8.75 minus 4.75 at 88.
Where you work you are extremely fortunate
you have a beautiful high-end auto lensmeter,
set to read to the nearest 0.125 or 1/8 a diopter step.
You put the glasses into the auto lensmeter,
line up everything just like you should,
you hit the print button and the ticket prints out,
and it says it's a plus 8.875, minus 4.625 at 86.
It is 1/8 a diopter strong in the sphere,
and 1/8 of a diopter weak in the cylinder.
Not terribly unusual, actually.
So let's figure out first what our tolerance is.
Let's grab our ANSI sheet and read it correctly.
Sphere meridian power, stronger than plus 6.50.
And we certainly have that.
That tells us our tolerance is plus or minus 2%.
I read across and it tells me a cylinder value
of greater than 4.50, certainly have that.
Is plus or minus 4%.
And I look down a little bit more.
Tolerance on the direction of cylinder axis,
anything over 1.5, certainly over 1.5,
gives me plus or minus two degrees.
So that's where that stuff comes from.
Good.
2%, 4%, plus or minus two degrees.
What is my allowable tolerance for 8.75
that is plus or minus 2%?
8.75 times .02, gives me 0.175.
You with me?
Okay.
So I've already done that for you.
There's my 0.175.
8.75 plus .175
is 8.925.
8.75 minus .175
is 8.575.
This range, this number to this number,
is the range of tolerance for 8.75
when we have plus or minus 2%.
Now, you have to be super, super careful here,
it is so easy to go wrong.
This side of our board, we are comparing
what we were supposed to have, what we ordered,
what we want.
What is the tolerance for the number we actually wanted?
What did we get?
We got this.
Does this fall between here and here?
Sure.
Probably like right about there, right?
So within that tolerance, our sphere checks out.
4.75, 4.75 times .04
is .19.
That's my tolerance in diopters.
4.75 plus .19
is .494.
4.75 minus .19 is 4.56.
The range of tolerance for 4.75, plus or minus 4%, is this.
Does what I actually got back from the lab, .4625,
fall between these two numbers?
I'd say yeah, it's probably
like right about here somewhere, right?
My cylinder checks out.
So far, so good.
I am told that my axis can vary
as much as plus or minus two degrees.
What do I have?
I wanted 88.
What do I have, 86.
My range, 88 plus two, 90, 88, minus two, 86,
there is my 86, I am good.
This job would pass.
I could call up my customer and say,
"Hey, come on in, pick up your glasses."
That is it.
There is no Prentice's formula.
There is no what if.
There is no comparing anything to something else.
There's your tolerance, that's what you ordered.
This is what you got, it falls within the tolerance
allowed for those powers.
You're good to go.
Let's do one more.
Are you ready for example number two?
Good, here we go.
You ordered a minus 9.25 minus 3.25 at axis 93.
You have got a gorgeous high-end auto lensmeter
set to read to the nearest .125 or 1/8 diopter step.
You've placed the glasses in the auto lensmeter,
lined everything up correctly, hit the print button,
and the ticket tells you you actually have a minus 9.50
minus 3.00 at 92.
Are you going to be able to call up the customer
and tell 'em to come and pick up their glasses or not?
Let's figure out what tolerance is for 9.25, 3.25 at 93.
Well, let's see.
Sphere meridian power stronger than 6.50, certainly.
Tells us we have plus or minus 2%.
Our cylinder falls between minus 2.00 and minus 4.50.
So that's gives us .15 plus or minus.
And obviously our cylinder value is well over 1.50,
so we have two degrees there.
We are taking the tolerance for what we actually wanted,
9.25 times .02
gives us our 2%, which is plus or minus .185.
9.25 plus .185,
9.35.
9.25 minus .185,
gives us 9.06.
Does what we actually got, minus 9.50,
fall between here and here?
The range of tolerance of 2%, plus or minus,
for the 9.25 we actually wanted.
No, it doesn't.
It out here someplace, it's no good, no.
Job would not pass for sphere power.
Let's see what happens with our cylinder.
Our cylinder, 3.25
plus .15 gives us 3.40.
3.25 minus .15,
3.10.
Does our 3.00 fall between here and here?
No.
It would be here, it's outside the tolerance range
for this given power.
The cylinder, no.
Gonna have to reject this job.
Would axis have made it?
Just for curiosity's sake.
93 plus two is five,
93 minus two is 91.
Hey, we have a winner.
Okay, our axis actually woulda been okay,
but, well, too bad.
That job would go back to the lab to be remade,
you could not call the customer and tell 'em
to come and pick up their glasses.
They fall outside of tolerance.
And that is all there is to it.
Next week we have Verification, Final Inspection part three,
where we tackle vertical imbalance.
In the meantime, please go ahead
and hit that subscribe button down there on the corner
if you're watching me on YouTube.
If you're watching us on Facebook,
please give us a like,
and make sure that every lens
you are doing verification, final inspection,
applying of tolerances to, comes from Laramy-K.
(cheerful upbeat music)