It's fall, but I'm not fitting pumpkins.

[drk]

Some patients have pumpkin heads, but not this particular one. We ordered a simple poly polar sunlens for about a -2.00 patient in a plano sun frame and got this back. Is the source of error?

a. the computer didn't know it was sunwear, an oddly flat BC was generated, and no one over-rode Mr. Roboto on order entry?
b. that's the wrong kind of bevel?
c. Luxottica doesn't have the right kind of bezel in their plano sunwear, and I'm dumb for trying?


I would like to know the way to prevent pumpkin sunglasses.

[Kwill212]

I wouldn't say 3.25 is an oddly flat base curve for that Rx.

The lens needs to be smaller, or inclined, and/or order a higher base curve with freeform optimization or, cut back the bevel on the handstone, or increase the faceform and optimize the lens with this new wrap angle, or take the temples off make the endpiece angle more acute and then put it back on.

[drk]

Thanks for the good suggestions.

Question about the bevel: that's the "hide-a-bevel" (old terminology?) approach, right? The bevel is put a 1/2 mm back from the lens front, which I normally appreciate. Does the resultant flat slab-o-plastic posterior to the bezel prevent the eyewire from "rolling" around the back of the lens edge? Is that a thing?

I.e., if the lens were tapered posterior to the bevel, would the lens fit the bezel differently enough to make it "relax" around the lens? Also, is this concept behind your suggestion to make the lens smaller? That is, so it has a little room?

[Kwill212]

Thanks for the good suggestions.

Question about the bevel: that's the "hide-a-bevel" (old terminology?) approach, right? The bevel is put a 1/2 mm back from the lens front, which I normally appreciate.

Yes, I'm not aware of any front of lens distance requirement, jut that the lens edge goes straight back posterior to the bevel(and straight forward anterior to the bevel if there is sufficient lens thickness.

Does the resultant flat slab-o-plastic posterior to the bezel prevent the eyewire from "rolling" around the back of the lens edge? Is that a thing?

Yes.

I.e., if the lens were tapered posterior to the bevel, would the lens fit the bezel differently enough to make it "relax" around the lens? Also, is this concept behind your suggestion to make the lens smaller? That is, so it has a little room?

Yes, and Yes.

Ideally this problem would be solved at the frame manufacturing level, but don't hold your breath for that.

[Uncle Fester]

These days I'm forever touching up minus lenses at the top shoulder when they are cut like this to allow me to heat just the hinge areas and bend the frame to correct the splay.

It usually lasts for a few days and by then they've gotten used to the gradual loosening.

Back when I edged on an old Optronics I almost always used the 5 degrees cutter blades and the occasional 16 degree blade to minimize this greif of minus lenses.

Forget who said this is an acetate problem frame manufacturers created in the way they can make a cheaper injection molded frame and it's now ubiquitous.

[CME4SPECS]

Is there some reason you can't heat the end pieces to make them curve inward and take the curve out of the temples? It shouldn't be that complicated!

[drk]

1. I don't expect lab work to look like this.
2. There are metal hinges that may loosen. (I guess I could take them off.)
3. Zyl oversize ladies sunglasses are always coming back in for a readjustment, even when they're initially perfect. Why cause frustration from square one?

[CME4SPECS]

I'd have that fixed, before you had it packed up, ready to return!

[Uncle Fester]

I'd have that fixed, before you had it packed up, ready to return!

Cutting a big hole in the bottom of the pumpkin doesn't count.

[Kwill212]

1. I don't expect lab work to look like this.

I've said it before and I'll reiterate it again. The best solution here, for the practice and the patients, is in-house edging. Let's say you are able to train your lab to make these frames come back exactly as there are with demo lenses, without the pumpkin fit. Next patient comes in for lenses in this exact frame and they actually do have a pumpkin head. Then what? This isn't a one off situation. Unless the person glazing the frame is the same as the person who fit and adjusted the frame on the patients head, final outcome can not be optimal.

[Lensman11]

These frames started as Plano sunglasses and are designed a certain way for that purpose. The back of the frame is higher than the front to prevent the lens from leaving the frame on frontal impact. This problem is easily solved all that is needed is an incline bevel the hide-abevel is inclined upward instead of straight back to clear the frame and this will eliminate the problem you have encountered. If you look at the bevel on the planos they probably not a v bevel they usually appear as one sided for the same reason. We used take silly putty and press it into the frame groove and remove the putty to see and measure the height of the back relative to the front so you could create a bevel with the correct dimensions. I know you can do this in the MEI edgers not sure about others.

[Uncle Fester]

We found use #18!

1. In 1968, Apollo astronauts took it into orbit to secure their tools in zero-gravity.
2. Physical therapists use it for rehabilitative therapy of hand injuries.
3. It can also be used therapeutically for stress reduction (and entertain you during boring meetings.)
4. Amateur CSIs can use it to lift fingerprints.
5. It can be used as a drumhead resonance damper.
6. You can wrap it around a pencil and use it as a grip.
7. Use a few balls of it to practice juggling.
8. You can use a thin layer of it as a thumb cover for counting money quickly.
9. Easily locate important items in your home (like flashlights or candles) during a power outage by marking them with the glow-in-the-dark variety.
10. Wrap it around your soda can and it will keep it cold.
11. Roll a ball of it on the floor to help find a lost contact lens.
12. It’s great for removing hair and lint from your clothes.
13. It can be molded into replacement dice for your favorite board game.
14. You can use it to open a twist-top bottle without hurting your hands.
15. It can be fashioned into a worm and used as a surprisingly effective fishing lure.
16. Stick it under your dog’s bowl so it doesn’t slide all over the floor.
17. It can also be sculpted into a boat for your pet hamster.
18. We used take silly putty and press it into the frame groove and remove the putty to see and measure the height of the back relative to the front so you could create a bevel with the correct dimensions.

[Lensman11]

You can also press it against a newspaper and it will remove the ink lots of fun with the comics. #20