Laminated Dive Mask RX

**CCGREEN** · 01-07-2015, 12:05 PM

Here is the Rx to be used.
+3.00 +1.00 X 75 +2.75 Add 2.0 Base out
+5.75 +1.50 X 05 +2.75 Add 3.0 Base out
Will be using FT 28 clear glass.

What I would like to do is have this Rx ground on a flat base curve so that I can laminate it onto the inside of a dive mask. I have done this many times with a myopic Rx and it works very well . But I have reservations as to how well the pt will do with a Rx like this.
The reason for laminating is to help reduce fogging that you get when you use a mask with a frame mount inside it. Using a frame is not totally out of the question, no doubt that would work just fine, but it is the last resort.

Any input? Suggestions?

Thanks in advance.

**erichwmack** · 01-07-2015, 12:08 PM

Cool idea, we dont get many requests for dive masks in AZ. Do you know the vertex distance of the mask? I would think a dive mask would have a large vertex and with RX it could be a problem. I also think with this RX and a flat BC there will be lots of HOA. The good news is that glare will be almost zero due to it being under water

**CCGREEN** · 01-07-2015, 12:18 PM

No sir. I do not know what mask is to be used yet so therefore a vertex is yet to be determined. I am with you thinking that the hyperopic Rx could be the problem. But what is HOA?

**MikeAurelius** · 01-07-2015, 12:40 PM

Just a caution, some people do have adverse affects when wearing plus cylinders.

I do mask lenses all the time, uncuts though.

Couple of issues with mounting on the inside: thickness of the lens impacting the silicone sealing ring, especially with the amount of base out prism combined with the power, and then the thickness of the lens being a heck bringing the lens surface very close to the eye, probably touching the eyelashes. Remember that the sealing ring compresses the mask to the face. You are going to have to ensure that the lens isn't so thick that it drives the lens into the eye.

A much better way to do this is to mount the lenses on the outside of the mask, and then compensate for vertex distance. It's an easy process to make these, we'd use plano base lenses, and just swap the lenses left to right in order to get the correct mounting.

Use a clear UV setting cement, such as NOA 61 from Norland.

This particular Rx is out of my processing range, so I can't help you there.

Good Luck!

**erichwmack** · 01-07-2015, 12:57 PM

Originally Posted by CCGREEN

No sir. I do not know what mask is to be used yet so therefore a vertex is yet to be determined. I am with you thinking that the hyperopic Rx could be the problem. But what is HOA?

Higher Order Aberrations

**MikeAurelius** · 01-07-2015, 01:14 PM

But HOA isn't much of a problem with glass. And any that exist will be damped down by the water.

**mshimp** · 01-07-2015, 01:15 PM

Compensate Rx to: OD: +3.50 -0.75 X 165 2.0 BO
OS: +6.62 -1.00 X 095 3.0 BO

Use 1.60 HI or 1.70 HI. Ground to 1.0 edge. Use # 61 norland UV curing glue like Mike said. Cross fingers

**CCGREEN** · 01-07-2015, 02:43 PM

Thanks for the outside mount idea Mike. But I have never nor do I think I ever would mount a lens to the outside of a dive mask. Primarly on account of the harsh environment a dive mask is subject to. Protruding from the front of the face plate like that I could see it getting knocked off and getting scratched real quick. If I cant put it inside I will not do it. I have a reputation of doing good work that I value. As far as the thickness of the lens goes and the mask being compressed closer to the eye. I had not taken that into consideration because I am dangerously assuming there will be enough room. And to be truthful I bet a Rx like this will be out of most labs range to do on a PL base. Its looking more and more like this will be a frame mount.

mshimp....thanks for the idea of using High Index. That one slipped right past me. And thanks for the compensated Rx.

**MikeAurelius** · 01-07-2015, 03:52 PM

I've done front mounts on pluses, never that high, you are right.

**Robert Martellaro** · 01-07-2015, 04:01 PM

The strongest meridian is +7.25 D. Who's willing to make a glass saddleback with that much power? Even if you could do it, the sweet spot wouldn't be much better than a pinhole lens. I would try a one day disposable CL and cross your fingers on the prism, the latter easily bonded to the mask if there is diplopia.

**Paul Smith LDO** · 01-07-2015, 04:13 PM

Originally Posted by CCGREEN

Here is the Rx to be used.
+3.00 +1.00 X 75 +2.75 Add 2.0 Base out
+5.75 +1.50 X 05 +2.75 Add 3.0 Base out
Will be using FT 28 clear glass.

What I would like to do is have this Rx ground on a flat base curve so that I can laminate it onto the inside of a dive mask. I have done this many times with a myopic Rx and it works very well . But I have reservations as to how well the pt will do with a Rx like this.
The reason for laminating is to help reduce fogging that you get when you use a mask with a frame mount inside it. Using a frame is not totally out of the question, no doubt that would work just fine, but it is the last resort.

Any input? Suggestions?

Thanks in advance.

If these are used for scuba diving, keep in mind that water with magnify objects approx. 22%. I'd try dumping the prism and alter the add power to an intermediate distance; that would allow your pt. to use their dive computer and camera/video. Keep in mind that once they get top side they can put their glasses on

**CME4SPECS** · 01-07-2015, 04:14 PM

Use the spherical equivalent, dive shops sell nothing but spherical equivalent. Mount them on the inside, the vertex distance will be out there somewhere around 20+mm, it won't be a problem, and that BO prism is helping your thickness nasally. I'd just get a std. size blank and mount it.
Of course you will need to get the decentration correct

**optical24/7** · 01-07-2015, 04:42 PM

I'm not a diver, but is an Rxable goggle an option for scuba? That would make it easy-peasy.

**CME4SPECS** · 01-07-2015, 04:56 PM

Originally Posted by optical24/7

I'm not a diver, but is an Rxable goggle an option for scuba? That would make it easy-peasy.

lens "plates" are available for dive masks, they are spherical only. If you ever go somewhere that rents snorkeling or dive equipment, they actually rent the plates to go into masks.

**Paul Smith LDO** · 01-07-2015, 05:03 PM

Originally Posted by optical24/7

I'm not a diver, but is an Rxable goggle an option for scuba? That would make it easy-peasy.

No, you require a tight seal (no pun intended) to ensure that no water can enter the mask and impede your vision.

**CCGREEN** · 01-07-2015, 05:32 PM

This pt is a local orthopedic surgeon who had lenses laminated to the inside of a dive mask......get this... 30 maybe 35 years ago by a family wholesale lab here in town that has long since closed its doors.
I believe he showed me the mask a few months ago and if I recall correctly one of the lenses has long since been MIA.
Since it was so long ago there could be a fair amount of difference in the Rx.
None the less hes coming in tomorrow so that we can discuss which direction to go with this. I have a feeling he is wanting to do some laminating again. And I can understand why.
I am lucky that I work with a OMD who dives and is also hyperopic but not near as bad. So between him and I we can come up with a Rx that should work pretty damn good.

**Fluegge Optical** · 01-07-2015, 05:48 PM

We do this strong plus stuff all the time, no need to do a spherical equivalent. Once you decide on the rx to use, we can make the lenses for you with the bifocals, either D-28 or D-35's.

Send us the mask pd's and bifocal heights and we'll do it for you. We do lenses that the "specials only labs cant do, daily!

**Gizzo** · 01-07-2015, 08:06 PM

I'll vouch for that!! I've seen the Fluegge family work magic...

Originally Posted by Glenn Fluegge

We do this strong plus stuff all the time, no need to do a spherical equivalent. Once you decide on the rx to use, we can make the lenses for you with the bifocals, either D-28 or D-35's.

Send us the mask pd's and bifocal heights and we'll do it for you. We do lenses that the "specials only labs cant do, daily!

**CCGREEN** · 01-08-2015, 09:24 AM

Thanks for the offer Glenn Fluegge. I will keep you in mind if we decide to go that direction. A D-35! in clear glass! in that Rx! Plano base! That would be so awesome! You think like I do. Throw all the other optical clutter out of your mind and don't over think the job. If you have the equipment no reason it cant be done. So many are so quick to just say no only because they have never heard of such.

**mshimp** · 01-08-2015, 04:12 PM

For your information I would of had the lens made at Glenn Fluegges. Small world!

**CME4SPECS** · 01-08-2015, 05:13 PM

It's nice to see that some are still willing and able to do saddlebacks. The last time I did one, I had a real hard time finding someone to do it. I ended up having Carskadden Optical in Zanesville Ohio do it, they are owned by the big E so probably wouldn't do it now.

**jefe** · 01-08-2015, 05:23 PM

http://www.scubaspec.com/

**MikeAurelius** · 01-09-2015, 08:47 AM

Saddlebacks? Not on this job, unless we have a different definition of saddleback. This is a straight forward plus cylinder. By definition, a saddleback is a lens that on the same side has a plus curve couple with a minus curve. For example: a lens having a surface curvature on one side of -2.00 diopters coupled with a +5.00 diopter cross curve.

**drk** · 01-09-2015, 09:48 AM

Awesome thread, guys.

I hope there are more of you around to do such stuff in the future, but I worry.

Question: does it have to be glass to be bonded? I assume so.

I understand that you'd have to use a fused segment to get a flat front (vs. a curvier, same index seg in plastic), ergo all BFs for dive masks must be glass for that reason, right?

Do you just order a plano base semi-finished blank?

**MikeAurelius** · 01-09-2015, 10:04 AM

Originally Posted by drk

Awesome thread, guys.

I hope there are more of you around to do such stuff in the future, but I worry.

Question: does it have to be glass to be bonded? I assume so.

I understand that you'd have to use a fused segment to get a flat front (vs. a curvier, same index seg in plastic), ergo all BFs for dive masks must be glass for that reason, right?

Do you just order a plano base semi-finished blank?

Yeeeesssss...mostly.

The NOA 61 mentioned above forms a "somewhat" flexible bond, however, it will break loose if torqued. Most dive masks still use flat glass plate (scratch resistance), and bonding glass-to-glass is always recommended. If you want a bifocal of any type, the lens has to be glass for the reasons you mention. I've seen some CR-39 single vision bonded to glass lenses, but from my diving days, the guys always complained of scratches and/or debonding. Divers routinely either spit or use a specially designed defog spray on their masks, and if there is even one particle of sand, the lens (if plastic) is going to have a hairy scratch on it.

Yes, both X-Cel and Vision Ease make plano base fused bifocals (and trifocals), X-Cel goes up to a D-35 and I think a 7x35 in plano base.