Monday, May 18, 2009

Rejuvenate Your Eyeglasses

I was so disgusted.
I spent almost $400 on my last set of eeyeglass and in barely a year the lenses were so fouled up from little tiny scratches that I was peering through a haze. The eyeglass guy told me that the anti-reflective coating on my glasses was fragile and that it "checkers" when it gets scratched. Of course the warranty for the coating was only good for a year.

So I bought a replacement set of lens for an older set of spare glasses I had, but this time I ordered glass lens with no coatings smeared on them. The blasted things killed my ears and punched deep crevices in the bridge of my nose. I had them re-adjusted but after a half hour or so - same thing. I can almost use the dents in the bridge of my nose as foxholes.

So I went to the interweb tubes to see what could be done. I googled "scratched eyeglass lenses" and found a reference to Armor Etch. This is a glass etching cream that you place in a stencil over glass. Leave it in for five miinutes or so and it etches the stencil pattern into the glass.

But it also removes the anti-reflective coating from plastic or polycarbonate lenses.
Look here.

It really works like a charm. I got a 3 oz. bottle of Armor Etch from our near by artsy fartsy store (Michaels) for $15; ran home and cleaned my year-old messed up glasses real good. Then I smeared this stuff over one of my lens on both sides with a Q-Tip.

I left the etching solution on for about five minutes and then rinsed it off under running water, used some eyeglass cleaner to get the rest of it off and then dried the lens with one of the kids' old diapers that we keep stuffed in a kitchen drawer just for this purpose.

It was like a miracle. It took two sessions with the Armor Etch but all those scratches were completely gone. But something else showed up. The characters O and 22 now show up just where the progressive trifocal portion of the lens starts; it is off center to the exterior or "outside"side of the lens - on both lens in exactly the same spot. I really can't notice it when I am wearing them but I still wonder why those markings are there.

1 comment:

Bifluoride said...

Happy to see things worked out for you.

That said, I can't believe people use this stuff so casually and then post about it on the internet recommending other people to do the same.

This is 21%-27% ammonium bifluoride. Crystal finishing people try to use nitric, oxalic, and sulfuric acid to avoid having to use ammonium bifluoride because it is too dangerous. More dangerous than sulfuric acid and people are recommending using it on your eyeglasses... poison to fix eyeglasses that you put over your eyes. People assume this is safe and assume this is dilute because it is sold in craft stores. Keep in mind that craft stores also sell just about every unregulated poison. If it were dilute and safe, would it etch glass? Would they put skin contact may be fatal on the label if it was safe?

I'm not saying that this does not work as it most certainly does. I have a couple of pointers though.

Don't do this inside.
Take the eyeglasses out of the frames.
If you mix this with water, you have created a hydrofluoric acid solution.
Do not heat this. You do not even need to use hot water.
If you come into severe contact, go to the hospital, but use calcium gluconate gel if you have it (probably not) or topical milk of magnesia after flushing well for at least 15 minutes.
If you come into contact, it will not hurt. What it will do is penetrate to the bone and cause somewhere between irritation and cell death for several days.
If you spill some, don't casually clean it up.
If you can't afford eyeglasses, you probably can't afford going to the hospital for fluoride poisoning treatment.
Don't try to neutralize this casually. Ever try to neutralize vinegar? Same concept applies, go very slow. Use chalk or small limestone chips. Or, better, take it to a hazardous waste disposal site and pay them to deal with it.
Please don't hurt yourselves trying to get reflective and scratch-prone prescription eyeglasses.