Anti-Radiation coating

[Albert]

Hi all , I m new here and I just found this forum yesterday .
I m so excited that here are so many 'buddies' talk about Optical related topics here .

I m an Optometrist from hongkong and our company own about 5-6 retail stores and a factory for frames/lenses producing in there (it's '5-6' because one will open in March :) ). Of course , we are also developing our online business .

The quality and the come out of new technology of Optical pruducts are always at the top of the world . However I don't really understand why the pricing level of the optical products are always very low in HongKong , I think it's related with the HK enconmy or something ....

Anyway , the following what I really wanna say in this thread .

Do the optical stores in your countries have 'Anti-radiation' coating ?

'Anti-Radiation' coating is a conductive coating which can block ELF/VLF E-field radiation from damaging our eyes . It's a new technology that apply to Ophthalmic field .


How often do you customers add this coating ?

And normally how much for this ?

This coating is very hot in HK since nearly all our lenses are AR coating included already .


Thanks for your attention

Yours,
Albert

[Jim G]

I'm aware of EM coatings but curious as to why they're so popular in Hong Kong? Most research I've read sorta says there's no danger (maybe unless you live right on top of high voltage transmission lines).

[Albert]

Jim G ,

Yes , EM wave do not directly 'damage' your eyes . They are just the wave with higher frequency/wave length than normal light .

But do you remember one of the main reason of increasing short sight ? - Tiredness .

Reading near things like books , TVs , Computer monitors for a long time will increase your myopia . This is not only because of your lenses are used to reading short distance to getting thickered
but also the tirdness of your eyes lead the ciliary muscles become 'lazier' to contract ( more likely to loosen )

Strong Light , EM waves are the main sources to lead your eyes getting tired . Anti-radiation conuctive coating can successfully blocks 99.8 % of EM waves . This technology are commonly use on computer screen filters . And now getting use commonly on ophthalmic lenses .

Anti-Radiation coating is popular in HongKong because our houses are really small ( the distance from sofa to TV usually not more than 3-4 m ) but the size of TVs are huge @_@
Children watch TV / playing TV games at home all the day leads their myopia increase very fast .
Anti-Radiation coating helps a lot to reduce the speed of their growing myopia .


I know this passage may be just a bunch of 'rubbish ' for many of professionals here but all I can say ...
I m not a professional . My father and other staffs are Optometrists but they are not able to write english posts .
I get all these knowledges from them so I m just tryng to translate and speaking for them :)

Please reply here if there are any wrong info in this post .
Thanks for taking time to read this sh*t

:hammer: :p

[coolme]

Sorry to bring up this old thread, but is there any creditability to what 'Albert' said about anti-radiation coatings?

Thanks.

[DocInChina]

Sorry to bring up this old thread, but is there any creditability to what 'Albert' said about anti-radiation coatings?
Thanks.

It is not that new technology. We have offered it on our product for over 5 years. We do not typically have a demand for it outside of Asia. I have not read any real scientific studies about its benefit but we still offer it. When it first came out we had a Geiger counter type instrument that would make rapid clicking sounds when held in front of computer screens or other light emitting objects and when the EMI blocking lenses were placed in between the "Geiger counter" and light emitting source the Geiger counter ceased to make the clicking sound.


Doc

[Jacqui]

Doc:

Are these also called EMI coatings??

[DocInChina]

Doc:

Are these also called EMI coatings??

Yes. We refer to it as an EMI coating.

[alternety]

ELF/VLF radio is lower frequency/longer wavelength than light. It makes no sense to me that a lens coating can block these frequencies. Nor that it would be useful if it did.

At ELF frequencies the non-ionizing radiation is very penetrating (used for submerged submarine communications) and because of thier long wavelength they are quite non-directional unless you are working with an antenna many times the width of a human eye (orders of magnitude). This sort of radiation, being non-directional in this case, would not be limited to comming from the front; hence through the lens. A long time ago I worked on a transmitter/receiver pair that worked no lower than 300 KHz (that is above [higher frequency, shorter wavelength] the ELF/VLF range - VLF is 3-30 KHz and ELF is 3-30 Hz) and the antenna was a pair of wires (dipole) 150' above terrain, and about 1.5 miles long to get good sensitivity with very high performance receivers. Submarine communications sites had antennas of 14-28 miles long. By far the most prevalent EM exposure is from the 50/60 Hz from electrical power systems. People have been arguing for years whether or not this is harmful. Generally the studies say no. One result that shows up from time to time is attempts to correlate 60 Hz (power in US) to childhood luekemia. Again not an eye issue and certainly not filterable. This stuff is pervasive in any area with a well distributed power grid.

Lenses blocking magnetic or electromagnetic fields of any intensity would be extremely unlikely. There are relatively few things that block magnetic fields and they are generally not particularly transparant. Make them into a coating so thin it is transparent (don't know if it can be done) and they still would not be effective in a lens. Electromagnetic fields can be blocked by shielding properly constructed to isolate the protected area. Generally this involves surrounding the protected item and usually providing a current path for the intercepted radiation.

Cathode ray tubes intrinsically generate some low energy x-rays (way, way above radio frequencies - see footnote). Standards from about the time of very early color televisions require electronic circuits or other techniques (glass has some lead in it) that severly limit even this soft radiation. These soft x-rays could possibly be blocked by a lens coating but you are much more likely to get much more, and very much more energetic, radiation from outer space (cosmic rays, gamma rays, X-rays, etc.). These are non-directional and not stoppable. And they cause damage. Ride in a commercial jet and the dose goes up quite measurably. Same damage from natural and man-made radioactive sources in the environment. Some old orange/red glazed pottery used Uranium for a colorant) and there is the Radon in your basement/house..

Summary - Ah you want an EMI coating. Would you also be interested in a used bridge near Brooklyn, at a very good price.

Other frequencies for comparison (each prefix to Hz is 1000 times higher than the pervious):

VHF television (channel 2-6) FM radio = 54 -120 MHz
Satellite TV > 3 GHz
Visible light = 300 THz/1 micro meter wavelength
Soft X-rays > 300 PHz
Gamma rays = 30-300 EHz

[Jacqui]

The thing is that one of my Far East suppliers keeps telling me about EMI coatings (they actually look like AR)

[Chris Ryser]

ELF/VLF radio is lower frequency/longer wavelength than light. It makes no sense to me that a lens coating can block these frequencies. Nor that it would be useful if it did.

Thanks........that was a very informative and interesting post

[chip anderson]

But to be really effective don't you have to wear the tin or aluminum foil helment?