Fused +12 Button

[Cindy K]

HELP! A low vision client came to us asking for a -1.25 distance with a +12 add button (no idea what his condition is, I wasn't involved in the dialogue). Anyone here know where we could get a pair of these? I'm thinking a fused button, but can't seem to find any labs that do these any longer. Anyone?????????

[MarcE]

Epic.
But I'm sure some LV experts will have the lowdown for you.

[mlm]

Cindy K,

Eschenbach has a product called the UniVision Low Vision Lens. It's a 22mm button that attaches directly to the patient's spectacle lens. The powers go from 8D to 40D, and are removable. We've used it once for a patient and he loved it.

It's funny that you mentioned a fused button. We're trying to find someone who'll do that with base out prism for a LV patient with a homonymous hemianopsia. No one wants to touch it.

[Jacqui]

It's funny that you mentioned a fused button. We're trying to find someone who'll do that with base out prism for a LV patient with a homonymous hemianopsia. No one wants to touch it.

Try a Franklin bi instead

[Cindy K]

Cindy K,

Eschenbach has a product called the UniVision Low Vision Lens. It's a 22mm button that attaches directly to the patient's spectacle lens. The powers go from 8D to 40D, and are removable. We've used it once for a patient and he loved it.

It's funny that you mentioned a fused button. We're trying to find someone who'll do that with base out prism for a LV patient with a homonymous hemianopsia. No one wants to touch it.

Hi MLM

Try these guys down in Vermont- http://www.chadwickoptical.com/hemianopia.htm

(They also do the button I was asking about) Thanx for the direction to Eschenbach- I'll talk to them also!

[Dave Nelson]

If I understand the problem with hemianopsia, the objective is to use a spectacle mounted prism cemented to the lens, and placed at the critical angle, which turns the surface into a mirror, and reflects a field towards the area where there is no vision. You may need some calculations to come up the apical angle of the prism, and the angle of placement to acheive the critical angle. Prisms commonly used in binoculars use the same principle, and it would not be a stretch to suggest you obtain a prism from an old pair of binoculars and do some trial and error with it. The ability to grind such a prism, surface it to, and cement it to the carrier lens should'nt present any real difficulty for a premium lab tech, but the cost in doing it by hand could be prohibitive. If there are any "stock" spectacles of this type, I am unaware of any. Good luck.

[mlm]

Dave,

That's exactly it. That's why a franklin bi won't work Jacqui. The prism in this case needs to be set in the temporal side of the right lens so that it acts like a "side view mirror", giving him an image of the area in the blind spot. We've tested it with a fresnel prism, so we know it'll work for him.

We ended up sending the frame and lens to Epic Labs. Hopefully things won't run afoul with customs.