Oleophobic longevity?

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02-09-2017, 11:03 AM
Browman

Oleophobic longevity?

So I've reached the point in my career where I'm starting to see people come back with two-to-four year old glasses, and a common complaint I'm getting is that the lenses seem to smudge and retain dirt easier than on dispense. The majority of these are Recharge, and some EX3s. I know I've run down Hoya on the boards, but, the quality of their ARs was never one of my many issues. Help a relative noob out-- is it normal for an AR to lose its' oleophobic properties after that period of time, or is this just another reason for me to hate on the big H? Is there something in particular that causes a breakdown-- heat, improper cleaning, etc.-- that I could advise patients to avoid? Has anyone encountered another AR whose oleophobic properties have a longer shelf-life?
02-09-2017, 11:14 AM
Mick

Run them through the sonic cleaner for a minute or two. It clears out the "grease" that collects in the nooks and crannies of a frame. Otherwise your cleaning cloth picks up some of this collected matter as your are swirling it around the surface of the lenses. It will work wonders for you and your customers in better cleaning of the lenses. At home your customer can soak their glasses in a glass of warm water with some Dawn dishwashing detergent for a few minutes. Rinse them under running water, and TA-Da, easier to clean. Of course the age of the lenses is also a factor, oleophobic topcoats don't last forever.
02-09-2017, 12:51 PM
CCGREEN

Better yet remove the lenses from the frame and drop frame only in the ultrasonic.
My personal experience a few times I left the lenses along with the frame in the ultrasonic to long and coatings on the lenses started coming off. Then they looked worse then when you put them in the ultrasonic. Time or two of that and I now always remove lenses and clean them separately.
02-09-2017, 01:03 PM
Chris Ryser

Oleophobic or in original wording "Hydrophobic Coatings" ...........................

Quote:

Originally Posted by Mick

Of course the age of the lenses is also a factor, oleophobic topcoats don't last forever.

Oleophobic or in original wording "Hydrophobic Coatings" are not hardcoatings and do rub off with the amount of cleaning they take over time.

This is why we have come up with a liquid replacement product that can be applied out of a small 30ml spray bottle and works just fine.

It will be shown by "DAC Europe" at the Milan "Mido 2017" this February 25/25/27.

It can be applied by the optician or sold to their patients.

Check it out at: ===========>
http://optochemicals.com/arspray.htm
02-09-2017, 02:26 PM
AngeHamm

Quote:

Originally Posted by CCGREEN

Better yet remove the lenses from the frame and drop frame only in the ultrasonic.
My personal experience a few times I left the lenses along with the frame in the ultrasonic to long and coatings on the lenses started coming off. Then they looked worse then when you put them in the ultrasonic. Time or two of that and I now always remove lenses and clean them separately.

I have also occasionally seen the ultrasonic craze lenses. I now only put frames in. I'll clean the lenses by hand or with a toothbrush and some dish soap.
02-09-2017, 02:51 PM
Tallboy

Quote:

Originally Posted by AngeHamm

I have also occasionally seen the ultrasonic craze lenses. I now only put frames in. I'll clean the lenses by hand or with a toothbrush and some dish soap.

Yeah me too. If its CR39 with hardcoat only I will sometimes let them go in, glass as well. Any other material or coating and those bad boys are coming out of the lens.

EDIT: Funny you mention your spray Chris, I just got off the phone with your company this morning inquiring about some more, The french man was very nice.
02-09-2017, 03:55 PM
Mick

I believe the key to ultrasonic cleaning is don't drop them in the cleaner then take a break. a minute or two MAX. This is from my lab friend owner who said it was ok for a short time. The cleaning ultrasonics in an AR system is much more powerful than most of us have in the store. But he did warn of too much time.
02-09-2017, 04:10 PM
Uilleann

To be clear - unlike stated above, OLEO (oil), and HYDRO (water) PHOBIC (repellent for our purposes), properties of an ophthalmic lens are absolutely NOT the same thing. And one property CAN wear faster than the other. Though most manufacturer literature seems to indicate the treatments aren't designed to last longer than about 2 years - which is the maximum SRx prescription length generally used across the country, and accepted as a standard of care. One thing that can be done for pt's, is to use one of the scratch warranty remakes close to the 2 year mark. Then the pt gets a new lens, with the associated reset of the surface repellent properties.
02-09-2017, 07:55 PM
RT

Quote:

One thing that can be done for pt's, is to use one of the scratch warranty remakes close to the 2 year mark.

Seems like that might be defrauding your lab if the lens isn't scratched.
02-09-2017, 08:18 PM
Uilleann

Quote:

Originally Posted by RT

Seems like that might be defrauding your lab if the lens isn't scratched.

Not at all. They build the cost of two replacements into every lens they sell. Even discounted, you better believe they aren't loosing money hand over fist on lens warranties. And show me any patients lens, that after two years doesn't exhibit at least hairline cleaning scratches...and I'll show you my pet unicorn Woodrow Caillou Thurston...the Third. He's BOSS! ;)
02-09-2017, 11:40 PM
Chris Ryser

to be even clearer than above.........................

Quote:

Originally Posted by Uilleann

To be clear - unlike stated above, OLEO (oil), and HYDRO (water) PHOBIC (repellent for our purposes), properties of an ophthalmic lens are absolutely NOT the same thing. And one property CAN wear faster than the other.

to be even clearer than above.........................

the chemical formula and application for both above mentioned features is exactly the same identical one.
02-10-2017, 10:36 AM
Uilleann

Quote:

Originally Posted by Chris Ryser

to be even clearer than above.........................

the chemical formula and application for both above mentioned features is exactly the same identical one.

Except in most large lens manufacturers processes. :) They are exclusive. Not everyone buys magic juice from you alone Chris. :)
02-10-2017, 03:50 PM
Tallboy

Quote:

Originally Posted by Mick

I believe the key to ultrasonic cleaning is don't drop them in the cleaner then take a break. a minute or two MAX. This is from my lab friend owner who said it was ok for a short time. The cleaning ultrasonics in an AR system is much more powerful than most of us have in the store. But he did warn of too much time.

I'm sure he is right - however once lenses are exposed to the outside world they may not act accordingly. I've had AR come off by cleaning with alcohol. I'm sure something else had caused some kind of breakdown. Long story short - I'm not going to be the one who gets blamed for someone elses booty brand AR coming off or crazing in my ultrasonic
02-11-2017, 12:42 AM
Chris Ryser

......................not everyone does buy magic juice from Chris,

Quote:

Originally Posted by Uilleann

Except in most large lens manufacturers processes. :) They are exclusive. Not everyone buys magic juice from you alone Chris. :)

That is actually a fact,.......................not everyone does buy magic juice from Chris,

but some of them have been doing so for years.
02-14-2017, 09:45 AM
AngeHamm

Quote:

Originally Posted by Tallboy

I'm sure he is right - however once lenses are exposed to the outside world they may not act accordingly. I've had AR come off by cleaning with alcohol. I'm sure something else had caused some kind of breakdown. Long story short - I'm not going to be the one who gets blamed for someone elses booty brand AR coming off or crazing in my ultrasonic

+1. Ultrasonic is for frames; toothbrushes are for lenses.
02-14-2017, 10:27 AM
Chris Ryser

+1. Ultrasonic is for frames; toothbrushes are for lenses..........................

Quote:

Originally Posted by AngeHamm

+1. Ultrasonic is for frames; toothbrushes are for lenses.

.................and all that if you do not forget that the Hydrophobic coatings do come off in time with the help of the abrasion of cleaning.
02-17-2017, 06:13 AM
Chris Ryser

A new layer of "EASY CLEAN" can be applied out of a 30 ml spray bottle .............

Quote:

Originally Posted by Chris Ryser

.................and all that if you do not forget that the Hydrophobic coatings do come off in time with the help of the abrasion of cleaning.

A new layer of "EASY CLEAN" can be applied out of a 30 ml spray bottle in a few seconds, and it also has "AntiFog and Antistatic" properties as a benefit.
When AR coated lenses with a hydrophobic / oleo phobic slick coat start getting tired and harder to clean, the original coating has been rubbed off through the cleaning action, and you can re-apply and refresh it with a new slick coat over the old one in seconds, and your lens surface will work again as when it was new.

For the first time shown at MIDO 2017 in Milan on the following weekend March 25.

See all of it at:
http://optochemicals.com/arspray.htm
02-17-2017, 11:27 AM
Pete Hanlin

Disclaimer- I am employed by Essilor.
In the manufacture of anti-reflective coatings, the same process is used to make the lens oleophobic and hydrophobic. Basically, you're putting a "double-sided" molecule on the surface of the lens. One side of the molecule loves to stick to things (usually, this side has SiO2) and this is the side that attaches to the lens surface. The other side of the molecule is fluorinated and doesn't like to stick to water (basically, it creates a low tension surface, so water, lipids, etc. tend to "bead up").

There are several different manufacturers who produce the type of chemical described above. Some provide a "denser" layer of molecules than others. Basically, the more fluorinated molecules you can pack on the lens, the lower the surface tension will be and the higher the contact angle (the angle formed by a water droplet when it sits on the lens- the higher the angle the more hydrophobic the surface will be). As Chris mentioned, all hydrophobic surfaces will degrade over time, because the fluorinated molecules detach with use (especially during cleaning, etc.). The trick is to pack as much of the stuff on at the beginning so as to leave the surface easy to clean over a very long period of use.

In theory, you could pack the surface so densely that nothing would stick (I've seen a cool R&D video of a droplet of water "bouncing" across a lens surface- because the surface tension of the lens is so low the water cannot adhere at all). Of course, realistically speaking the edging process limits how "non-stick" the surface can be (since you have to be able to adhere a leap pad to the lens to edge it). Basically, the limit this imposes is a contact angle of 108 degrees (above this contact angle, a leap pad will not reliably maintain adherence to the lens during edging).

For Crizal no-glare coatings, a "Pad Control Layer" is used to allow us to create a lens with a surface angle upwards of 116 degrees. Basically, the control layer is an extra, temporary layer put on the lens in the AR chamber, and it makes the lens "sticky" enough to be edged. Once the lens is edged, the layer is wiped off- leaving the surface fairly densely packed with fluorinated molecules. As with all AR lenses, the coating wears off with use- but it remains easier to clean longer because it started out with more molecules. Eventually, ANY hydrophobic layer will wear down (and I'd argue if your EX3 lenses are making it to 2-4 years before they lose their cleanability, that's pretty good- I would hope the patient is purchasing new lenses by that point).

BTW, the reason the lens becomes so difficult to clean after the hyrophobic layer has worn off is the outer layer of most AR coatings is made of SiO2 (if you remember from earlier, SiO2 loves to stick to stuff). Therefore, once the hydrophobic layer is worn off, you have a fairly sticky lens surface. If you need to continue using the lenses at this point, you can apply something like Chris' spray (which, I suspect, serves to decrease the surface tension- which makes the lens easier to clean).

Sorry for the length, but the guys on my team talk about this stuff all the time- so it's been drilled into my brain (one of them used to be in the coating section of our R&D, and the other produced the first Crizal lens 25 years ago- so they really geek out on this stuff... I'm more of a PAL guy personally).
02-17-2017, 11:49 AM
merrymaker

Good info Pete. Thanks for the post
02-17-2017, 01:32 PM
Chris Ryser

the same process is used to make the lens oleophobic and hydrophobic.................

Quote:

Originally Posted by Pete Hanlin

Disclaimer- I am employed by Essilor.

In the manufacture of anti-reflective coatings, the same process is used to make the lens oleophobic and hydrophobic. Basically, you're putting a "double-sided" molecule on the surface of the lens.

....................................... As Chris mentioned, all hydrophobic surfaces will degrade over time, because the fluorinated molecules detach with use (especially during cleaning, etc.).

Thank you Pete, I have been missing your regular posts on OptiBoard that always made good sense and showed the know how.

I really hope that with above statements, the record has been set straight again and OptiBoard members will have to agree with the facts, as stated by somebody that is in a qualified position to do so.
02-18-2017, 01:50 AM
Chris Ryser

Pete Hanlin, a long time, and one of the formerly very active and liked .............

Quote:

Originally Posted by Browman

So I've reached the point in my career where I'm starting to see people come back with two-to-four year old glasses, and a common complaint I'm getting is that the lenses seem to smudge and retain dirt easier than on dispense. ............................................................ ............................................................ ..Is there something in particular that causes a breakdown-- heat, improper cleaning, etc.-- that I could advise patients to avoid? Has anyone encountered another AR whose oleophobic properties have a longer shelf-life?

Thanks to Pete Hanlin, a long time, and one of the formerly very active and liked OptiBoard members, the above original question, has been redirected to its right path and proper solution.

And our OptiBoard member "Browman", who posted the basic question on this thread got his final answer by the "Director Technical Marketing, of Essilor of America" which is part of the largest Worldwide AR coatings supplier.
02-28-2017, 03:48 PM
Happylady

It's great to see you posting Pete!

I've heard that over use of cleaners like Dawn strip the top slick coatings on AR lenses and make them harder to clean. Is this true, Pete? I always tell my patients to use rarely and to stick to Simply Dawn which isn't as strong if really needed.

I also tell people to wash their microfiber clothes and to rinse their lenses under running water if they are more than smudged.
03-01-2017, 06:41 AM
Chris Ryser

Cleaning with soap will do no harm.....................

Cleaning with soap will do no harm.

What is the damaging action is the abrasion from rubbing the layer. The more abrasive the means, the faster the layer disappears.