I just picked up my pair of Pearle Vision
"computer" glasses and aaahhh.

There seems to be 2 small "water marks" in the center sides of
each lens, a total of 4.  One looks like this (ignore the dots,
I had to insert them to hold the white space.  google shifted
everything over to the side)

.___
( | )     "supoz to be a circle with line pointed down
..|
.100

the other looks like

.___
( | )     "supoz to be a circle with line pointed down
..|
..CS

They create a blurry zone which I was told to ignore.
But there also seems to be a 'vertical' bump in the lens - both
of them.  As you train you eye on a single spot and move your
head from side to side, there is a section of the lens that
puts the spot out of focus.  It's like a transision zone that
I would expect horizontally in a standard bifocal.

You have progressive computer glasses.  The central part of the lens is set
at the correct power for computer use; the power  increases towards the
bottom of the lens to the power needed for reading and decreases towards the
top of the lens to the power needed to view 6ft  to 8 ft.  You are noticing
the tranistion zones.

Progressives do not work if you keep your eye on a single spot and move your
head from side to side.  The rules for using a progressive:
Point your nose at what you are looking at and move your chin up and down
until the clear spot is found.

Also, is it possible that there were additional "water marks"
that would have been in the vertical blur zone?  I get the
impression that they failed to polish something away.

They will be returned today.

Questions:

1. What are these marks for?

2. What do they mean?

The marks are to identify the lens type and progression rate.  They are
etched on all progressives and many single vision lenses and cannot be
removed.  They are used by the edging lab to put the lenes in the correct
position in the frame and by the dispenser to measure whether the lab
provided the correct lens in the correct positon. The marks are different on
the nasal and temporal sides and help to identify right and left lenses
during edging.

3. Are they chemically etched or physically placed?  I not
sure if I see a ripple when I reflect light off the lens
or printing.  I'd say ripple as in seeing a dent, but again
I'm not sure.

4. Does this plasic material come off a roll?  Would explain
the irregular positions of these marks when comparing the
two lenses.

I've had saftey glasses that had even more pronounce marking,
but the markings were way up in the corner - some place I
would never see. And they look printed or etched.

On the computer glasses one lens has this mark just outside what
I would call the sweet spot.  The the markings also seem to
roam.  One lens has the marks near the sweetspot and extreme
edge, the second lens has the marks both to the outside edges,
like this plastic came off a roll.

If you cannot see clearly using the "point nose..." method of positioning
your head, Pearle may have mismeasured where the centres should be.  They
can check that when you take them in.

Expect a "sweet spot" and to take some time to learn to use them.  If you do
not adapt after two to three weeks, you may need to get a non progressive
lens.

Dr Judy

0. Do not post on newsgroups using rtf or html. Always use text. Change the
option in your newsreader.

1. The etchings are using to identify the progressive lens manufacturer,
model, and usually lens material. They should be outside the field of
vision. The should also include a number which represents the reading add
power.

Lens also come with markings on them to identify the center (horizontal and
vertical) of the lens. This is important because the center of the lens must
be placed at the proper fitting height in the frame for your vision. These
will wash off. Ask Pearle to remove any remaining markers in the field of
vision.

2. Check this link for progressive lens id's suing the etchings on the side
of the lenses. The document is a few years old, and does not include all
manufacturers. This may be a problem for Pearle, since they don't use well
known brands (or make their own).
http://katzandklein.com/images/LensIdentifierGreen2002.pdf

4. The lens markings (etched permanently on the sides, and those that wash
off in the middle) are always in the same place in the round lens, which
usually is about 75mm  - 80 mm before it is cut to place in your frame. When
the round lens is cut to put in your frame, they may have cut the lenses so
that it appears the markings are in different places. This may be OK if your
eye positions are asymmetrical, or it may indicate that the lenses/frame
were not measured/cut properly, or that the person who did the frame fitting
on your face made errors (fairly common with progressives).