Fixing Warby Parkers

[Robert Martellaro]

LCA on axis?

Barry's client is experiencing 3.5 prism diopters (-5.00 x .7cm) on the primary gaze, or on axis.

The LCA is 3.5Δ/30 = .12Δ.

Not significant, but not voodoo or pseudoscience- the vision and comfort suffers, especially when combined with the other errors.

You must have missed this article:

http://www.2020mag.com/l-and-t/41604/

B

Unlike some technical articles I've read in the trades, this piece is filled with useful information and is top-down, dead on balls accurate.

[Slim]

+1 Robert! I printed it off and gave it to my opticians to bone up a lil more on it.

[Barry Santini]

Barry's client is experiencing 3.5 prism diopters (-5.00 x .7cm) on the primary gaze, or on axis.

The LCA is 3.5Δ/30 = .12Δ.

Not significant, but not voodoo or pseudoscience- the vision and comfort suffers, especially when combined with the other errors.

Unlike some technical articles I've read in the trades, this piece is filled with useful information and is top-down, dead on balls accurate.

Heck...I think Robert has nailed it! Who here really considers applying ANSI-style standards to the off-axis viewing? if the power tolerance for SV is 0.12D for this Rx, then the use of non-aspheric poly in this fitting situation, without even consider the off-OC astigmatism error in the primary gaze position, is, IMHO, showing a callous disregard for proper optics.

Thanks for the compliment, Robert!.

B

[DC Optix]

1. Remade in CR39 AR FF SV with POW included
2. Supplied 4.25 BASE curve (Frame bevel curve was 2.8D)
3. Use ME1200 Variable bevel mode to taper edge thickness as to prevent frame temple "splay"
4. Edge-tinted the lenses to reduce ring effect and blend with frame.

Photos are attached to tell the visual story. Will probably have to mail eyewear to school (I prefitted them). Won't know client response until next week.

Discussion.

Barry

Barry...super impressed with your dedication on this particular job. I know this is a little off-topic, but could you expand a little more on the edger settings/techniques you used to prevent temple splay? This is a common problem in our office and I would like to investigate the possibilities of addressing it. Thanks in advance!

[Slim]

Lemme see if I can answer that one.

On my 9000LE I can change the base curve of the bevel. So if you have say a high - lens, On the nasal and temple edges, you can have the bevel more in the middle of that outer thickness rather than towards the front. trade off is that you might have some of the lens protruding out in front of the frame. Personally I dont like that, but if its a frame thats not easily bent or heated to fix temple splay then id do it.

[optimensch]

ahhhh. temple splay. I think it deserves it's own special thread.

I will say this - UV cured glue as a "shim" on the back of the frame front where the temple abuts has been very highly effective. The UV glue we use seems to adhere well to acetate, though on TR90 or other injection molded material not so well....

[Golfnorth]

ahhhh. temple splay. I think it deserves it's own special thread.

I will say this - UV cured glue as a "shim" on the back of the frame front where the temple abuts has been very highly effective. The UV glue we use seems to adhere well to acetate, though on TR90 or other injection molded material not so well....

Never heard of that stuff. Any idea on it's availability?

Regards,
Golfnorth

[optimensch]

Well I was first introduced to the UV glue because we sell rimless Lindberg frames and this is the product they recommend. the particular glue is "dymax 3094". there are probably distributors in the US, as it is an American product. Any UV lamp will cause it to harden after a few minutes. I am lucky to have a high intensity UV torch which does the job in 2 seconds, but it is not a requirement!

Sometimes roughing the surface with a little sandpaper will aid in adherence, but generally I just put a dab. It is the quickest fix, it goes un-noticed almost everytime because the UV glue is crystal clear and doesnt whiten (bloom) the way crazy glue or other cyanoacrylates do.

[Paul Smith LDO]

For those of us (unfortunate or not) who have put FFSV CR 39 lenses into a WP frame, I have found that a roll on the temporal edge of the lens can reduce some of that splay induced by WP. In some cases I just roll the entire edge lens, it just depends on what you feel will work best.

[MakeOptics]

Heck...I think Robert has nailed it! Who here really considers applying ANSI-style standards to the off-axis viewing? if the power tolerance for SV is 0.12D for this Rx, then the use of non-aspheric poly in this fitting situation, without even consider the off-OC astigmatism error in the primary gaze position, is, IMHO, showing a callous disregard for proper optics.

Thanks for the compliment, Robert!.

B

Checking off axis powers to ansi is so 60+ years ago that was scrubbed from the ansi standards half a decade or better ago. You may remember me mentioning that a few years back with very little regard from most, the current standard has the dispenser put trust in pick of base curve to the lab which puts the trust in the manufacturer providing the right base curve charts or tables for the LMS. Going off base happens often enough and the dispenser can actually fault due to ansi for not meeting the base curve within a diopter.

Years back the vertex distance compensation formula was included int he ansi at the time due to the change in prescription being considered prescribing by doctors, hey wanted to know just how their prescription was being changed and rightly so. Nowadays the prescription compensation varies on the same exact job ordered a week apart and the formula is proprietary.

[Barry Santini]

Barry...super impressed with your dedication on this particular job. I know this is a little off-topic, but could you expand a little more on the edger settings/techniques you used to prevent temple splay? This is a common problem in our office and I would like to investigate the possibilities of addressing it. Thanks in advance!

Variable bevel mode is Santinelli's name for when the "hi-curve/wrap" bevel mode is used on a non-wrap frame. The result is a tapering back of the front and rear bevel lips of thicker lenses, even plus (think nasal-side interference).

AS others have stated, this can be accomplished in a number of ways.

B

[Chris Ryser]

Dispensing Trivex, The Decathlete of Lens Materials -

By Barry Santini

It’s been just over a decade since PPG introduced Trivex, the lightweight,durable mid-index lens material that PPG positioned as an upgrade from itsindustry-standard CR-39 monomer. Although Trivex has gained many supporters,some eyecare practitioners remain hesitant to use it. Their objections havecentered on three concerns: price, thickness and need. ..............................

- See more at: http://www.2020mag.com/l-and-t/41604....G0r6HZYK.dpuf

I missed it too, but read it just now...................and learned quite bit. Good writing Barry.

[DC Optix]

Variable bevel mode is Santinelli's name for when the "hi-curve/wrap" bevel mode is used on a non-wrap frame. The result is a tapering back of the front and rear bevel lips of thicker lenses, even plus (think nasal-side interference).

AS others have stated, this can be accomplished in a number of ways.

B

I didn't realize that was even an option...great to know! I came into my current practice after they had already put our Santinelli in, and I'm not in the lab much (due to the fact that I have a great lab team), so I haven't really played around with it much. Definitely going to go discuss this with my lab supervisor! Thanks so much for the information!

[DC Optix]

Lemme see if I can answer that one.

On my 9000LE I can change the base curve of the bevel. So if you have say a high - lens, On the nasal and temple edges, you can have the bevel more in the middle of that outer thickness rather than towards the front. trade off is that you might have some of the lens protruding out in front of the frame. Personally I dont like that, but if its a frame thats not easily bent or heated to fix temple splay then id do it.

Thanks, Slim! I've got a 9000 as well...going to get working on this today!

[Barry Santini]

Lemme see if I can answer that one.

On my 9000LE I can change the base curve of the bevel. So if you have say a high - lens, On the nasal and temple edges, you can have the bevel more in the middle of that outer thickness rather than towards the front. trade off is that you might have some of the lens protruding out in front of the frame. Personally I dont like that, but if its a frame thats not easily bent or heated to fix temple splay then id do it.

You can see exactly this in the photos.

barry

[Matthew]

Barry

Did all of your creative changes take her headaches and eyestrain away??

Do you think that it is possible the RX from the OD was off?

[Barry Santini]

Barry

Did all of your creative changes take her headaches and eyestrain away??

Do you think that it is possible the RX from the OD was off?

Mother just reported back that all is very sharp and comfortable....even when used at the computer.

Eyestrain and headaches: GONE.

Rx was a duplicate of her previous glasses made by me.

B

[Matthew]

Mother just reported back that all is very sharp and comfortable....even when used at the computer.

Eyestrain and headaches: GONE.

Rx was a duplicate of her previous glasses made by me.

B

BARRY 1

WARBY 0

Thats a score in the making!

[Gary N. Snyder]

Optician won !

[Chris Ryser]

Optician won !

Opticians would always win if they are quality wise, have the knowledge and use their thinking power