time again for new glasses

lorwolff · #1 12-18-2003, 09:54 PM

I primarily work with soft glass. However, I do like boro too.
I just don't have a lot of space to do a lot of switching around.

That said..., I am in need of new eye protection.
When I started out beadmaking, I used didymiums, and got headaches. I switched to prescription aura lens rose didys ( I think) and did fine.
Now I have a new Rx, and would like to order some clip-ons of the very very best protection I can get.
I read up on Aura Lens web site, but only got more confused.
Any simple answers for this simple gal????

Ray Ansin · #2 12-19-2003, 05:33 AM

I have woked borosilicate for over 35 years and gone through four pairs of Didyniums . New perscription lenses each time. I have tried the new lenses supplied by people like Auralens, a didynium cobalt? glass. Quite a pronounced blue colour. Although it does provide better contrast when boro glass is being worked. I still prefer the older rose didys for all glass working with no problems yet evident in the eye department. Getting perscription lenses is best as clip ons weigh heaps. They are not very expensive. My last pair purchased earlier this year cost about $250 US including my choice of frame. freight to New zealand from the US was an additional 15 dollars.
I did not get them from Auralens.
The only time that I need darker protection is when I am working Fused Quartz. Then I have dark green flip down clip ons.

MikeAurelius · #3 12-19-2003, 08:49 AM

Different people/situations have different requirements. What works for one person does not work for others, which is why my company offers a variety of filter products, not simply one size fits all like some companies offer.

That said, the AUR-92 does not contain cobalt - it achieves the blue color from the various exotic elements that give the material its unique filter abilities.

Lori - I'd suggest a pair of "next generation" didymium (AUR-92) filters plus a pair of welders clip on's for those times when you are going to work boro. You don't need dedicated boro glasses unless you intend to work boro all the time.

Ray Ansin · #4 12-19-2003, 01:46 PM

I have not yet bothered to put one of the new lens materials under an X RF machine for analysis.
As my ashumption regarding cobalt is out, could you please indicate what other elements contribute to its colour beside the probable Neodymium, Praseodymium rare earth content. Possibly Iron to absorb the IR present and this also absorbs the SW UV. It is a very unusual looking glass. You have me quite interested..
Also a querry to your reply. By saying that the new lens material should be supplemented by additional filtration, if you are continously working Borosilicate glass.
I say this slightly tounge in cheek, Is this new material inferior to the older mixed rare earth lens composition, where no additional filtration is required. Thousands of glassblowers world wide have used it for over four decades with few problems.

Ray Ansin

[url]http://www.glassbeads.co.nz

Other suppliers of specialised Didymium filer glass include, Wale, Mancine Optical, Phillips etc.

MikeAurelius · #5 12-20-2003, 09:16 AM

Ray --

A slight correction to your list -- Aura and Phillips are the only "manufacturers" of finished eyewear (you've already seen the issues about Phillips on my website), the rest are retailers who have no optical lens manufacturing capability. Mancine is an optical laboratory who grinds prescriptions.

I'd love to help you out - however, Schott considers its materials proprietary and refuses to release any data about the constitution of the lens material apart from generalities on the MSDS (material safety data sheet).

The AUR-92 raw material is actually superior to the older didymium in that it has a much deeper sodium flare filtration notch, as well as specific other notches designed to reduce or remove secondary colors, which enhance primary color vision, giving excellent view of the glass temperatures as it heats up.

Yes, didymium did serve its purpose quite well. The new material is taking its place, I'm expecting that "old fashioned" didymium as a product will be obsolete within the next 1-2 years, once remaining supplies of glass are used up. It will still be available, but at a very high price (supply/demand/price curve). The new material right now is less expensive than didymium, so the curve is already starting.

In the near and middle IR (infrared), both didymium and AUR-92 are lousy filters - this has been and is a concern as more and more people begin working borosilicate - until the last 5-10 years, the only major users of borosilicate glass were scientific workers (like yourself, I assume), who worked mainly with clear boro while constructing apparatus. There are documented cases of long-term eye damage in scientific workers, see Fusion for details. Right now, the only way to cut near and middle IR is to supplement the base material with an IR absorber, such as a green welding filter, or with a dedicated IR absorber, such as the Schott KG filters as covered in our Patent.

The problem with the green welding filters is that it also cuts visible light, which isn't a problem for color boro workers, but is for clear boro workers.

The problem with IR absorbers is the expense. The raw material is 30 times as expensive as the base AUR-92 material, hence the high price of the AGW series filters (plus the labor in making the wafers and lamination process).

Ray Ansin · #6 12-20-2003, 01:31 PM

Dear Mike.
Thanks for your detailed reply re aura lens material.
I did know that it was a Schott glass and so could not at that stage work out where you fitted into the overall picture.
From your reply regarding Mancine Optical. Do you also produce perscription lenses or supply the blanks so that they can be worked elsewhere. Due to being extreemly long sighted my script now is at the limit obtainable from a normal blank thickness That sentence is quite a mouthfull.
Have a nice day and watch out for the tiger . LOL.
Raymond

MikeAurelius · #7 12-21-2003, 09:21 AM

Ray - due to the special requirements for tempering this glass, we don't sell what are called "semi-finished" lenses. The glass, because of its constituent components cannot be chemically strengthened in the usual fashion, and if heat tempered (case hardened), requires a special time/temperature process.

We do have our own "in-house" laboratory, so we can process our own prescriptions without having to resort to outside facilities that we would have no control over. We are limited somewhat by the glass that we have available, prescriptions can be ground only in the range of (spherical correction) of -6.00 diopters to +4.00 diopters.

lorwolff · #8 12-21-2003, 08:52 PM

Mike,
I finally found the paperwork from my presripc. Aur-92 glasses from Auralens.
The glasses I have just are too heavy, and the Rx is old.
Are prescription glasses still heavy?
Are clip ons as effective for protection?

EyesOfTheWorld · #9 12-21-2003, 10:22 PM

I have no prescription, and no knowledge of didymium glasses. What should I get? I have been thinking just ordinary cheap-o rose didymium glasses. Any suggestions?

MikeAurelius · #10 12-22-2003, 07:27 AM

Nothing has changed as far as weight is concerned, unfortunately, especially when considering prescription alternatives. Glass is heavy when compared to plastic/polycarb. Clip on's will certainly be lighter in weight. You may also wish to consider the Table Shield as well.

eyes -- cheapo didymium glasses are fine, but the next generation filter (we sell as AUR-92) is a much better filter, and is the same price as didymium from almost all the suppliers.

Not many suppliers are offering didymium anymore because it is more expensive as raw material, and I expect it will be pretty much obsolete within the next year or so.

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