Need help with Access lens

[LENNY]

I need help in understanding an Acces near vision progressive lens!
I understand that they come in 2 adds: high and low
My question is :
If i have an RX needing +1.50 Sph for intermideate with +1.00 add for reading. How would the Lab figure out the RX (i mean what will it say on the invoice and what i will actuarly read on the lens 1) Power in full progressive height on the top?
2)Power in the add circle?
3) the highest power?

What are the power readings in the same regions on a RX
PL with +2.50add?
or PL with +2.00 add?
I am confused!!!!!!!!!!!!!!!!!!!!!!!!
Big time!!!!!!!!!!!!!
Is there anything better than this lens with an intermideate and near ability and as less periferal blur as possible.
What about using a regular progressive design with an intermediate rx instead of distance and an add??
Is this going to work?

[chip anderson]

Lenny: There may be some weird use for one but this is the first time I have ever seen an intermediate with a higher plus power than the reading power. No wonder you are confused.

Chip

[LENNY]

Thanks
Varilux had a lens called Readables but i think they dont make it anymore!

[m0002a]

If the traditional PAL Rx is +1.50 with a +1.00 add, the Access computer lens would be made with +1.75 in the intermediate area (on the top) and +2.50 in the reading area (on the bottom). Or in traditional PAL terms it would be +1.75 with a +.75 add. Just remember that the reading area is the same as a traditional PAL, and the base power is .75 less than the reading power.

The above example assumes that the .75 “low power range” is used (recommended for Access lenses when traditional adds of 1.50 or less are prescribed for a regular PAL). If the traditional PAL Rx has an add of 1.75 or more, then the 1.25 “high power range” is recommended.

Other brands of computer lenses use different algorithms. For example, the Rodenstock Gradal RD takes the regular PAL Rx and adds .50 to the base and subtracts .50 from the add. This is automatically done at the lab, the Optician just writes up the Rx as a normal PAL and the lab makes the adjustment.

Some Opticians create their own computer lenses from ordinary PAL’s by adding some customized amount to the base and subtracting the same amount from the add power. This enables the Optician to create a lens that is focused at a specific computer distance used by the patient in the base power for maximum viewing width, or to meet some other customized viewing need.

[icey]

the Rodenstock Gradal



zeiss makes the gradal rd;)

try the shamir office lenses

[m0002a]

"zeiss makes the gradal rd"

Oops, that's what happens when I post at 1:46 am (my time).

[Clive Noble]

We've dispensed hundreds of Access and are now into DeskTop also, the advantage with the DT is that it comes in 3 (minus adds!)
0.75
1.25
1.75

If you're looking for a slight distance portion too in this type of design, there's the old trusty AO Technica, but you need a deepish frame and have to be accurate on measurements

[Refractingoptician.com]

::

[Mark Sachs]

Gary--you may be right on that. But the advantage of the Access is the "progressive-like" power range from intermediate to near. That should give the patient a bit more flexibility if accomodation is an issue.

[LENNY]

To M002
Would +2.50 be the highest + power in the lens in Your calculations?
Or it will have more + on the bottom of the lens?
How deep is the corridor of this lens and also if you compare it to progressive how much wider would be the transition area in this lens?

[m0002a]

Lenny,

I just re-read your original post and I misunderstood the Rx. You wanted +1.50 in the intermediate area with 1.00 add for reading. I thought you meant +1.50 in the distance area and a 1.00 add.

The Access only comes in 2 adds, .75 and 1.25. So you cannot get a 1.00 add. Since 2.50 is needed in the reading area, then +1.75 would be the intermediate range on the top of the Access lens, and the .75 add for reading would be on the bottom (for a total of +2.50 in the reading area).

If you have some other Rx for the Access lens, just remember that you start with the TOTAL reading power, and then subtract either .75 or 1.25 to get the intermediate power on the top. As mentioned, other brands have different add numbers (Gradal RD comes in .50 add only, and Desk Top comes in .75, 1.25, and 1.75 adds, etc.).

You could fabricate a regular progressive with +1.50 with a 1.00 add to get exactly what you want. As to how a regular progressive would compare to the Access lens in terms of the corridor and width of transition area, I cannot answer that, but I know one very well respected optician who uses the regular progressives instead of the specialized computer lenses.

As mentioned above, a lined bi-focal would work well and be cheaper if nothing is needed in-between the +1.50 top and +2.50 (1.00 add) bottom.

[m0002a]

Unfortunately, I have not explained the Zeiss Gradal RD computer lenses properly in the above post. The Zeiss Gradal RD does not have a fixed add power of .50, or any fixed add power like the other computer lenses. The way it works is that the lab takes the regular Rx for a progressive and adds +.50 to the top and subtracts .50 from the bottom. For example if the normal PAL Rx is +1.50 with a 3.00 add, the Gradal RD will be converted at the lab to +2.00 with a 2.50 add (always add .50 power to the top and subtract .50 from the add power on the bottom).

In your case you wanted +1.50 on the top and a 1.00 add on the bottom. To get this in Zeiss Gradal RD you would turn in an Rx to the lab of +1.00 with a 1.50 add. The lab would add .50 to the top and subtract .50 from the add power to get exactly what you want.

Here is a quote from the Zeiss web page concerning the difference between the Gradal RD and their regular PAL (Gradal Top):

“The flow of progression of Gradal RD lenses is considerably different from Gradal Top [the regular Zeiss PAL]. The progressive zone [of the RD] stretches over a length of 25 mm. In direct comparison to Gradal Top, the [Gradal RD] progressive zone starts higher and ends lower. Therefore, you’ll always find a certain amount of add power in the fitting cross (in addition to the +0.50 D in the measuring point for distance power).”

I need to quit posting this late at night.

[Mark Sachs]

Let me take another crack at the Access.

As was noted, it has 2 powers. So, to end up with the +2.50 reading, you'd have a choice of either a +1.25 or +1.75 in the intermediate. (You can specify which. The +1.25 intermediate would use the "high power" shift.)

The people at SOLA say the best way to visualize the zones on Access is to imagine 2 80mm circles that overlap eachother by 10mm. That 10mm zone is the transition and is roughly in the middle of the lens (depending on how you fit it). The rest, top and bottom, are the full intermediate and reading powers. The aberration is pretty far off to the edges (esp. in the low power) leaving a very wide "channel".

I was with SOLA for a number of years and they had good success with the lens. The issue was that this was an expensive 2nd pair. But people who got it were quite satisfied.

[Refractingoptician.com]

::

[LENNY]

Next problem!

How do you measure the height for this lens?
And what PD do i use?

I love this lenses!!!

[Mark Sachs]

Lenny--Fit Access using the Near PD. As for height, dot at pupil center (like a progressive), figure the height in the frame and then SUBTRACT 5mm.

Good luck.
--Mark

[judyseyes]

Dear All: Zeiss Gradal RD, stands for "Room Distance". The top third gives room distance up to 10', thus the +0.50 power added to the Distance RX by Lab. the middle third is for intermediate, fitting cross or center pupil is located here, and the lower third is for reading, subtract +0.50, so near power remains unchanged.
Judy Johnson, Territory Rep, Carl Zeiss Optical

[LENNY]

Thanks everybody!

[Jim G]

Gary: First, I wear a PAL. I DARE you to get me back into a ST. It just won't happen. The Access, and other Computer/Work related lenses are probably one of the best functioning lenses available and also one of the least understood and utilized.

To your points: (1) Any product that requires this much explanation and forethought and still remains as clear as mud is doomed to marketing failure because :
(a) most labs run on minimum wage labour that does not understand optics and would be and are lost in trying to comprehend this subject.

Don't know where you're located (noticed the spelling of "labour" but, I respectively disagree. As a dispenser, all you have to do is give the lab the info. They will convert the proper powers for ANY of the lenses.

(b) many opticians can't easily explain the concept to each other or easily understand it without pen and paper in hand

You obviously have never tried any of these lenses. THEY WORK! What's to understand? You have lenses with extremely wide intermediate and near areas...with no significant "channels" to interrupt vision. They're working lenses.

(c) to be a runaway marketing success this product needs to be as much a no brainer as a Flat top is . To order it an optician should simply give the lab the NORMAL bifocal rx and then say "ACCESS PLEASE

You should be able to. Might try another lab. It's not a big deal!

You also noted pricing. Don't know what you pay but, some labs offer discounts if purchased with a PAL. Check around.

[m0002a]

Can anyone explain the difference between the Sola Access and Sola Continuum computer lenses?

[Jim G]

Mark, I'd like to hear the answer to that one too!

[Farhan Hassan]

Actual prescription of patient


R/E +0.75 / -2.00 180
L/E +0.75 / -1.75 170

Doctor prescribed For Access Lenses

-0.25 / -1.50 * 180 add +0.75
-0.25 / -1.75 * 170 add +0.75

Now i am confused Which Prescription should i give to the Lab tech. me also confused help me,,,

[Jason H]

These task-specific lenses cause a bit of confusion. At one time, each would reccomend doing something different for ordering which enhanced the confusion. My reccomendation is this - order the lenses with the full Dr.'s Rx like you would any other lens. Then make this explicitly clear to the lab - they understand all the differences between the different makes. These lenses work from the full reading Rx at the bottom of the lens and then "digress" ( think minus power going up the lens instead of add power which is plus power going down the lens). So on an Access lens you get full reading power on the bottom and either -.75 or -1.25 in a power change going up on the lens. Gotta think bottom-up. Hope it helps.

[Uncle Fester]

Actual prescription of patient


R/E +0.75 / -2.00 180
L/E +0.75 / -1.75 170

Doctor prescribed For Access Lenses

-0.25 / -1.50 * 180 add +0.75
-0.25 / -1.75 * 170 add +0.75

Now i am confused Which Prescription should i give to the Lab tech. me also confused help me,,,

You can not make the doctor's exact rx in the access. Minimum fit height 15mm and must be measured low.

Read post #9 from another thread-

http://www.optiboard.com/forums/show...la-Access-lens

[PRECISIONLAB]

To simplify things we ask our ECP's for the true Bifocal/Progressive RX and we adjust @ lab. In your case it appears the "actual" is an intermediate script only..and the Access Rx is a compensated intermediate with near. If you combine you will have .50-1.50 in the distance which is only .25 less than actual intermediate RX so working distance might have been adjusted.