Double D segs

[orangezero]

So, I had a patient the other day that wanted Double D segs for his job. He's worn them before. The problem is he has lots of neck problems from some injury's and the lower vision reading distance is further away than the things he needs to see above. Someone he talked to last time told him to get a higher ADD power in the top. After talking with my lab guy he said this was impossible to do, that no one made them like that.

So, my question is, what is the best way to handle this? I know they have those stick on adds, would this be a decent way to go?

I was thinking of just using some standard +2.00 FT 28 for the bottom and then for the top sticking on some +2.50 or whatever.

Anyone do this? I've never personally used those stick on adds. I realize they don't last too long, but what should I expect and which are the best?

thanks,

[CME4SPECS]

You should be able to get any add combo that you want. However you'll have to use glass. Vision Ease

[Jacqui]

:idea: Why not get a +2.50 add and turn them 180 degrees. Puts the higher add on top. ;) ;)

[For-Life]

:idea: Why not get a +2.50 add and turn them 180 degrees. Puts the higher add on top. ;) ;)

The problem here seems like he needs a +2.00 and a +2.50, and the lenses is only available with the same add.

[Jacqui]

Can get split adds

[mshimp]

check with xcel for split add powers. And jacqui is right.Turn them 180.

[chip anderson]

The suggestions made are good ones, but are you sure you have your facts right? I have seen many of these and the top working distance was always further away (requireing lower that reading add power) than the bottom..Chip

[orangezero]

thanks for the replies everyone.

yeah, I'm sure about the different adds. He has a factory job and there are some controls on the table he needs to see, and some screens down below. The screens above his head slightly are very close, hence the higher add.

thanks for caring.

I thought I'd ask on here because I'm constantly amazed at how often I hear people say, "oh they dont' do that" and then find out later it is available. I found it hard to believe no one in the whole US makes a Double D of differing powers. Now, the price might be a whole other story I guess, but still better than stick ons.

[CDOT]

younger dd 28 2/3 of total add on top. (or in your case the bottom...and yes just surface the blanks upside down Ive done it a dozen times.;)

[Robert Martellaro]

Now, the price might be a whole other story

I know what you mean; the CR39 double D35 that I fit last month cost me more than a premium 1.67 PAL (finished).

FYI the latest Frames Data lens book shows a CR39 DD35 with un-even adds in a six base .

If your client doesn't need distance capability you could use a ST and use the distance portion for the near on the downgaze and the segment on the top for the closer upgaze focal length. You can get ST28s with adds as low as +.50D and ST35s down to +.75D.

Regards,

[orangezero]

thanks again.

again to my other question, i know this isn't a good answer, but does anyone have experience with those stick on lenses? I thought they might be beneficial for some situations.

thanks.

[CME4SPECS]

I've used the Optyx 20/20, they work fine.

[dcdwn]

Some wholesale labs can make the add powers that you want and how you would like the segment placed. It is a special order , and will take some time.
One lab I know is B&B Optical in Johnson , Iowa . They do good work.


Don Price ABO/NCLE

[Ory]

thanks again.

again to my other question, i know this isn't a good answer, but does anyone have experience with those stick on lenses? I thought they might be beneficial for some situations.

thanks.

You're referring to fresnel lenses? We've discussed them a bunch in the past few months that I've been here

http://www.optiboard.com/forums/show...hlight=fresnel

http://www.optiboard.com/forums/show...hlight=fresnel

http://www.optiboard.com/forums/show...hlight=fresnel

They will likely work in some situations. If the lens is going to need cleaning often, be exposed to changes from hot to cold, or otherwise treated harshly you may want to trial with fresnels for the $20 but then do a cement on seg with your local lab.

[HarryChiling]

I am probably going to chop the spelling, but here we go use a ft 28 or 35 with wichever add power you need the surface the lens thicker and block the lens up again decentering and resurface the top portion only with the different reading prescription. This is called a "myoter bifocal" and I have done one a long while ago but it not only worked well, but it looked great and the patient had lots of comments from other plumbers. I have an equation around here somewhere wich will allow you to calculate the thickness you would need to resurface and the amount to decenter the lens. When I find it I will post, or Darryl might read the post and work the equation from his optical filing system "the brain";)

[OpticLabRat]

:idea: Why not get a +2.50 add and turn them 180 degrees. Puts the higher add on top. ;) ;)

Nice Answer!!!
I had a regular patient who wanted his D35 on top of his frames. I had to measure his seg ht from the top and surface the lenses upside down. I made several pairs for him.

His Occupation........

Ice Hockey cameraman.

He looks through the distance downward from the top of the arena to the ice, and looked up through his top reading portion to see his monitor.

I was happy to meet his needs

[dcdwn]

Here is how it is done , you take a round 28 mm bifocal grind the power that you want ,with the bifocal add you want. example rx -1.00 sph bif add is +2.00 seg ht 3 below ok now you want a +2.50 add on top grind a single vision lens to a +2.50 segment width of about 28to30 mm cemented to the upper part of lens with a 10to 12 mm between add powers . this is how bifical were made a long time back. It works fine. It is like when some one comes in wanting their rx put in a diving mask the lens are cemented on the inside of the lens plate.
This is not a press on add .

Don Price ABO/ NCLE