sv essilor 360 lenses upsidedown

**ih8wlmrt** · 06-29-2010, 02:26 PM

there is a question by a consumer about the markings on a SV essilor 360 digital lens- obviously no one answered it, but I have not used these lenses before(not an essilor kind of girl) and for my own future reference I would like to know the answer to this consumers questions. you never know when someone might come in with a pair of these and I would not know the first thing about them-don't want my customers to think I don't know everything about everything.
does it matter if these markings are upside down?
does it matter that the markings are not straight accross?
my instinct is it does not matter, but having never edged a pair and never having an E rep show up to tell me all about them I am completely clueless.

thanks

**Uilleann** · 06-29-2010, 02:35 PM

When in doubt, go to the source. Ask Pete. He'd know. :D

**Barry Santini** · 06-29-2010, 02:53 PM

My understanding is that the "engravings" on a Digital 360 SV lens are to be placed 4mm below the pupil.

I'm not sure if these lenses are rotationally symetrical, but I think not.

Barry

**WFruit** · 06-29-2010, 02:58 PM

It won't matter if they are upside down on SV, although I would question the competence of the lab not knowing which way is up. They should be in a straight line on the 180, even though as SV they can be surfaced and then rotated to the correct axis before edging. As I understand it, they are engraved after surfacing, which means that the engravings were done incorrectly (probably engraved backwards, ie right for left, left for right). Again I would question the lab to make sure they know what they are doing....

**Jubilee** · 06-29-2010, 05:28 PM

So they are a digitally surface lens.. now couldn't it possibly throw things off if they were upside. Taking into considering the pantoscopic tilt, and other position of wear measurements, might there be (though perhaps slight) difference between above the pupil and below?

**Uilleann** · 06-29-2010, 05:38 PM

Essilor SV 360 lenses are not ordered with POW measurements.

**blinkvelo** · 06-30-2010, 06:15 AM

Its very possible and likely that the software may have engraved the lens with the markings upside down and the lens itself is right side up. They should all be engraved correctly now.

**braheem24** · 06-30-2010, 06:28 AM

Originally Posted by Uilleann

Essilor SV 360 lenses are not ordered with POW measurements.

I'm sure they use default POW and it's not retroscopic.

**WFruit** · 06-30-2010, 08:54 AM

Originally Posted by Barry Santini

My understanding is that the "engravings" on a Digital 360 SV lens are to be placed 4mm below the pupil.

I'm not sure if these lenses are rotationally symetrical, but I think not.

Barry

From speaking to an Essilor rep and people at an Essilor "partner lab," the circles on the lens are part of the molded blank and are not "engraved." These should be on the 180 line of the lens. The engravings showing lens material are added after surfacing and are 4mm below these circles.

Here's the thread that started the discussion, with a very nice picture: http://www.optiboard.com/forums/show...be-upside-down

**For-Life** · 06-30-2010, 10:57 AM

You can send them with POW measurements and it should be fitted at the OC. So the fitting marks will be below the OC. If you put them upside down, the OC will be off by 8mm

**AngeHamm** · 06-30-2010, 10:58 AM

It DOES matter if they are upside-down, and they ARE to be aligned as an Essilor progressive, with OC 4MM above the 180 line.

I have a couple pair of these, and one of them was edged with one lens upside-down. They were dotted up and edged as a standard SV lens. It's not an enormous difference, and I'm still a binocular 20/15, bt the center field of vision is substantially wider with right-side-up lens.

The Zeiss Individual does the job a little better in my experience, but this is a cool lens for high myopes. When it's not upside-down.

**Happylady** · 07-01-2010, 11:03 AM

I'm glad someone asked because I was wondering the same thing.

**MarvinTheMartian** · 07-01-2010, 10:01 PM

Interesting; I have a high myope client who brought this very thing to my attention, complaining that for such expensive lenses he couldn’t see worth sh*t (his words). He pointed out the misalignment of the micro engravings as well. This was news to me (the lenses come to us inked and we edge them here), but it seemed possible that, since they have PAL-like engravings, perhaps these digitally-surfaced lenses are meant to be aligned like PALs, and the lab was not aware of this (as I wasn’t).

This client is a friend of a friend, so if he insists, I will have them remade with the circles lined up on the 180 as per PALs, unless I can prove the engravings don’t mean anything. Alternatively, if I can get proof that they are indeed supposed to be aligned this way, I may be able to get the lab to take responsibility; otherwise I’ll have to take a hit on these.

Any Essilor experts out there who can provide proof or reference material as to how these lenses should be mounted? Documentation from Essilor on the 1.74 SV 360 would be ideal.

Thanks.

**For-Life** · 07-01-2010, 10:34 PM

Question, why would you not line them up to match the engraving?

**MarvinTheMartian** · 07-01-2010, 11:45 PM

They come from the lab dotted up; the lab did not line them up to match the engravings.

**WFruit** · 07-06-2010, 10:17 AM

Ok, First, from Essilor:

Click image for larger version.

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The Circles are on the 180 line and should be on the same axis as the lens itself, with the OC in the middle. The engravings are 4 mm below the circles. But it's the circles that are used to layout the lens for edging.

Originally Posted by MarvinTheMartian

They come from the lab dotted up; the lab did not line them up to match the engravings.

I presume then that the lab did the edging.....

Bottom line: If the lenses are laid out for edging using the circles and they are straight, then the lens being upside down does not affect the optics (very much. I don't know exactly how much the 360 compensates the Rx to reduce peripherial distortion but this could be greatly affected). Note that the circles are also used for Surface blocking, and this is probably where the errors occured. The circles are part of the original molded lens, while the engravings are added after surfacing to identify they type of lens.....(I bet these are the same lenses Essilor uses for SV blanks for the Ideal, as it would make sense that they already have the circles in them, similar to the Seiko blanks used for their FreeForm lenses).

If the engravings are used (which they should not be) then the lens being upside down will mess the patient's vision all the heck up.

It's still very embarassing that the lab didn't know which way is up.....(remember, the enemy's gate is Down :bbg:)

**Pete Hanlin** · 07-06-2010, 12:54 PM

As the previously posted illustration shows, Essilor SV360 lenses have circles which are 34mm apart and are positioned along the 180 axis of the lens. Additionally, there is an "H" with three rays engraved 4mm below the circles (any material identification code- e.g., "P" for "polycarbonate" will be positioned between the H and the circle).

When properly edged/mounted, all four circles should be arranged in a line along the 180 line, and the "H" markings should be below the circles.

Best regards,
Pete

**MarvinTheMartian** · 07-06-2010, 04:51 PM

Thanks, Pete and WFruit. I will approach the lab with this information and have them re-do the lenses. Do you have a link to on-line documentation from Essilor that I can send to the lab to prove this point, and to ensure that this doesn't happen again? I may have to re-think my relationship with this lab...

I was looking for the WOW factor with this client and these FF lenses, so it will be interesting to see (no pun intended) what his reaction is with the properly-aligned lenses.

Thanks again.