Re: AR coatings are not durable long-termOn Wed, 16 Apr 2008 08:11:25 -0700 (PDT), SQ <onestatusquo@yahoo,com > wrote:
>I got an AR coating for the first time in my life, on high-index
>lenses.
>
>Before these, I had regular non-coated glasses that I used to clean
>with TP or Kleenex -
>the lenses held up well, no scratches. Always followed the same
>procedure: Wash with mild
>soap solution, clean while wet, wipe until dry. No problems.
>
>Tried cleaning these new AR coated lenses with Kleenex and what a
>mess. Caused several
>deep scratches and a myriad smaller ones. Never had that issue with
>non-coated lenses
>for 10 years, not one scratch.
Kleenex did not cause the scratches.
>So I switched to a microfiber cloth and cleaned very carefully, using
>soap-based solutions
>without alcohol, cleaning only when wet. The scratches stopped. But
>about 6 months later,
>the coating started coming off in chunks, started to see crazing,
>blurry spots while
>looking through the glasses. It's a disaster.
The coating process was done improperly, and/or it was a cheap coating.
>In a nutshell, with AR, I had issues with:
>
>1) Scratches
>2) Coating coming off
>3) Staining
>
>The coating I got is junk, plain and simple. Not sure what the brand
>is. I took it back to the
>store and they promised to replace with lenses with another coating.
>I hope it's a premium coating like Crizal and more durable.
I've only seen two or three coatings fail in the eight years or so that I've
used Essilor's Crizal. A consistently high quality product.
>Basically my conclusion is that not all AR coatings are created equal,
You got that one right!
>and that they are all
>high-maintenance.
Clean with soap and water, dry with a clean cloth, put them in the case when not
worn. AR or not.
>My next pair of eyeglasses will not have them. I
>never had issues with
>glare or anything like that, they fix a problem that doesn't exist
Surface and internal reflections, starbursting, light loss, and veiling glare
are real issues with optical lenses. If they don't bother you then skip the AR
on your next pair. However, your glasses may have been flawed from the get go so
it might be hard for you to judge the benefits or lack thereof.
>and reduce long-term durability.
Nothing lasts forever. Think of items that you wear every day that last ten
years.
>AR coatings are vulnerable to a multidude of things that non-coated
>eyeglasses are not
>sensitive to:
>
>Having highly acidic perspiration
Eats up frame finishes, metal and plastic, and sometimes the hard coatings on
the lens. Glass seems to be immune.
>Cleaning with Kleenex
is ok if there's no lotion added. I use Kimwipes at work. I wouldn't use them on
a coated lens that I was keeping for thirty years, like a photo or astronomical
lens. At home and for my clients I use/recommend Luminex's microfiber, made by
Toray Industries in Japan.
>Chlorine from swimming pools, salt in sea water - if you must wear
>your glasses while swimming
I've been in some pools where it felt like the chlorine was taking my skin off.
>Excessive heat, i.e. leaving them on the dashboard of your car
I wouldn't put my camera there on a hundred degree day.
>Hairspray
You'll need a solvent like denatured alcohol to get it off the frame and lenses.
>Acetone
Don't use this anywhere near eyeglasses.
>Windex, or any cleaner containg ammonia
Ditto.
>My last pair of eyeglasses without a coating lasted for 10 years
>without a scratch
>and was highly durable.
>IMO it's just a way to extract more cash from the consumer by selling
>these junk
>coatings, saying that you "need" them, like car dealers that push
>overpriced,
If you pay for junk then it was probably overpriced. How much did you pay for
this junk coating?
>unnecessary options.
Unnecessary for you, essential for me, and from desirable to essential for about
80% of my clients.
>I asked my optician if I could get a pair without
>AR coatings and
>was told "No", that explains everything.
I've heard that there's a chain of optical stores that's selling coated lenses
only- might be Sears (Cole National, now Luxottica). I don't recommend it for
everyone; some people are too lazy to clean their glasses everyday, some types
of Rxs, lens materials, and designs may not benefit as much from coated optics
as others, and might be money that could be better spent elsewhere in their
ophthalmic budget. Try this next time- tell the optician that you clean your
glasses twice a week, and then ask if you should have an AR coating. If they say
yes, then grab your wallet and run.
Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
Wauwatosa Wi.
~~~~~~~~~~~~~~~~~~
"Science is a way of trying not to fool yourself."
- Richard Feynman