Sunglasses with hi-index lens and AR coating?

Hi all:

I'm not sure if this group is the right place to ask about it. If I'm
posting on the wrong group, please accept my apology and would
appreciate it if you can guide me to the right group for the question.

My question is: I have a pair of sun-glasses with high-index lenses.
Everything's fine except that when the sun is shining on my face at a
high angle from the front, I can see my the reflection of my eyes and
face on the lenses. I've heard that high-index lens can do well with AR
coating. I'm wondering if sunglasses with high-index lens need AR
coating (some say it doesn't). Since it's expensive to get the coating,
I'd like to know if I do go get the coating, will the
seeing-my-face-in-my-glasses problem go away?

If the lenses were polarized polycarbonate lenses, will that problem be
there?

Thanks in advance for your response.


Charles

Sounds like you need an ar coating on the inside only. Often done on
high quality sunglasses.

w.stacy, o.d.

JustLikeToSay wrote:

> Hi all:
>
> I'm not sure if this group is the right place to ask about it. If I'm
> posting on the wrong group, please accept my apology and would
> appreciate it if you can guide me to the right group for the question.
>
> My question is: I have a pair of sun-glasses with high-index lenses.
> Everything's fine except that when the sun is shining on my face at a
> high angle from the front, I can see my the reflection of my eyes and
> face on the lenses. I've heard that high-index lens can do well with AR
> coating. I'm wondering if sunglasses with high-index lens need AR
> coating (some say it doesn't). Since it's expensive to get the coating,
> I'd like to know if I do go get the coating, will the
> seeing-my-face-in-my-glasses problem go away?
>
> If the lenses were polarized polycarbonate lenses, will that problem be
> there?
>
> Thanks in advance for your response.
>
>
> Charles

On 4/5/06 1:43 PM, in article AZVYf.533$gO.200@pd7tw3no, "JustLikeToSay"
<(E-Mail Removed)> wrote:

> Hi all:
>
> I'm not sure if this group is the right place to ask about it. If I'm
> posting on the wrong group, please accept my apology and would
> appreciate it if you can guide me to the right group for the question.
>
> My question is: I have a pair of sun-glasses with high-index lenses.
> Everything's fine except that when the sun is shining on my face at a
> high angle from the front, I can see my the reflection of my eyes and
> face on the lenses. I've heard that high-index lens can do well with AR
> coating. I'm wondering if sunglasses with high-index lens need AR
> coating (some say it doesn't). Since it's expensive to get the coating,
> I'd like to know if I do go get the coating, will the
> seeing-my-face-in-my-glasses problem go away?
>
> If the lenses were polarized polycarbonate lenses, will that problem be
> there?
>
> Thanks in advance for your response.
>
>
> Charles

In principle, it is easier to design AR coatings for high index glass, circa
n=1.9 than for lower index. High index glass will reflect more, almost 10%
per uncoated surface for n=1.9. That, by the way is a very high index for
ordinary glass. Until after WWII most people were able to survive uncoated
glasses quite well.

Bill
-- Ferme le Bush

Salmon Egg wrote:
> Until after WWII most people were able to
> survive uncoated glasses quite well.

Wasn't that because they weren't able to polish
them enough to reflect back then? -

-Quick