SUN GLASSES

At 11:02 13 June 2013, Doug Mueller wrote:
DO NOT FLY WITH NON POLORIZED LENS!
by doing so you trick your eye into opening wider
because of the
shade. Remember polorization is used to protect
from UV light. If
you open your eye wider by non polarized glass you
expose your
eye to that UV light. You will damage your eye much
quicker. It is
not a function of can you see your instruments or
not. Do not be
mislead into this kind of thinking......
Most glider canopies are not made with polorized
protection.


Er no, actually. Polarised sunglasses block a portion
of the incident light according to how it is polarised,
not by wavelength. Reflected light is partly polarised,
which is why polarised sunglasses reduce glare.

UV protection is accorded by the tinting medium.
There are plenty of substances out there that block
UV, just as there are tints that block other
wavelengths (hence coloured lenses).

There are a number of standards around for
manufacture of sunglasses based on opacity to UV
(no agreed international standard yet), including an
EN standard in Europe and an ANSI standard in the
US. These specify the maximum transmittance in the
UV part of the spectrum as a percentage of the
transmittance in the visible part.

Naturally your eyes will open wider if the amount of
visible light getting to them drops- the point is that a
very much less of the light getting through is UV.

I don't know about your part of the world, but in
Europe most good sunglasses are sold with a CE
mark indicating that 95% of radiation at 380Nm is
blocked.

None of this has anything to do with polarisation.

In short, check the specified UV transmittance.
Polarisation is just a personal preference.

At 11:02 13 June 2013, Doug Mueller wrote:
DO NOT FLY WITH NON POLORIZED LENS!
by doing so you trick your eye into opening wider because of the
shade. Remember polorization is used to protect from UV light. If
you open your eye wider by non polarized glass you expose your
eye to that UV light. You will damage your eye much quicker. It is
not a function of can you see your instruments or not. Do not be
mislead into this kind of thinking......
Most glider canopies are not made with polorized protection.


Absolute Nonsense. The UV that is damaging to eyes is that with a
wavelength less than 320nm. Looking at the chart on the Zeiss website here


http://tinyurl.com/qxfa6kj

you will see that nearly all the light below 500nm is blocked by the skylet
fun tint.

Furthermore, depending upon the type of perspex, your canopy will cut UV
below 400nm by a further 99%.

Suggestion: Buy a pair of polarized cheap sun glasses (sounds like a ZZ Top song). Then try them in your cockpit. If you like them, only they buy a nice polarize pair.

If I remember correctly in aviation catalogs I only see non-polarized. I read at Sporty's the following;

--- Why we don't sell polarized sunglasses ---
Many sunglasses today are polarized, meaning they use an optical filter to reduce glare. While this is fine for fishing or driving, it's a bad idea for pilots. That's because many cockpit instruments and glass panels have polarized faces, and polarized sunglasses will render these unreadable. In addition, the iPad screen will be blacked out in portrait orientation when wearing polarized sunglasses. Sporty's sells a wide variety of high quality sunglasses that do an excellent job of reducing glare--but without polarization.
----------------------------------------------

I use non-polarized Serengeti's. The better question is ... what tint is recommended for the lenses? Brown? Green? Gray? Yellow? Chartreuse?

- John

On Jun 13, 4:02*am, Doug Mueller wrote:
DO NOT FLY WITH NON POLORIZED LENS!
by doing so you trick your eye into opening wider because of the
shade. Remember polorization is used to protect from UV light. If
you open your eye wider by non polarized glass you expose your
eye to that UV light. You will damage your eye much quicker. It is
not a function of can you see your instruments or not. Do not be
mislead into this kind of thinking......
Most glider canopies are not made with polorized protection.

There has been some amazing misinformation posted on RAS but this post
has to take first prize!

Andy

On Thursday, June 13, 2013 1:14:14 AM UTC-4, Ramy wrote:
On Wednesday, June 12, 2013 3:27:26 PM UTC-7, noel.wade wrote: On Jun 12, 3:20*pm, wrote: I'm getting new sun glasses, should I get Polarized or not, what works best for flying gliders??? The ones I'm looking at are also anti-glare lenses. Thanks Glen If you use _ANY_ electronics in the cockpit at all (even a digital- display variometer), you do _NOT_ want polarized lenses. The lenses will appear to "black-out" those displays at some (or all) viewing angles. Also, some canopy materials will cause them to look like a checkerboard when viewed through polarized lenses. I won't bore you with the science/physics, but in general you're best off with non- polarized lenses for aviation use. --Noel This is incorrect. I am using tons of electronics in the cockpit with polarized with no problems. the only device I ever had a problem was with the rectangular butterfly display in landscape mode, but resolved it. I wouldnt fly with regular sunglasses as I find the polarized superior due to reducing canopy glare and increasing detection of clouds and traffic. Ramy

This agrees exactly with my experience. I have been using brown tinted polarized glasses for more than 30 years with good results. The Butterfly display is the only one that there was a problem with. problem solved by scrapping the display.
UH

At 14:01 13 June 2013, Andy wrote:
On Jun 13, 4:02=A0am, Doug Mueller wrote:
DO NOT FLY WITH NON POLORIZED LENS!
by doing so you trick your eye into opening wider because of
the
shade. Remember polorization is used to protect from UV
light. If
you open your eye wider by non polarized glass you expose
your
eye to that UV light. You will damage your eye much
quicker. It is
not a function of can you see your instruments or not. Do
not be
mislead into this kind of thinking......
Most glider canopies are not made with polorized protection.

There has been some amazing misinformation posted on RAS
but this post
has to take first prize!

Andy
There was no intention of misinformation. I am stating pure and
simple facts. Anti glare does not necessarily filter out UV light.
The comment about pilot sunglasses is a consideration.
Professional pilots look through polorized glass in their cockpits.
Looking through two pieces of polorized glass will give the
blanking effect that has been mentioned on this thread. In the
desert southwest antiglare is not sufficient protection from UV
light. It might be in places where the sun is not as intense. The
coments I made about the eye are not incorrect either. Thanks
for the prize Andy what ever it is. Just trying to protect glider
pilots so you can see me flying. Oh ya thats what FLARM is for.

If you are old enough to need readers to see the instruments (like I am), finding good quality polarized glasses with built in readers can be challenging. Maui Jim makes a few versions and they are very high quality, but very expensive too. I settled on SunCloud that has a few models with standard power readers for $60-$80 new on Amazon.

JohnDeRosa wrote:

I use non-polarized Serengeti's. The better question is ... what tint is
recommended for the lenses? Brown? Green? Gray? Yellow? Chartreuse?


Rose, of course. You must view the world through rose-colored glasses to
confidently fly cross country without an engine.

P7 unit

P7 has the best answer...

But Let's step back to facts, shall we?

Polarized lenses literally block light, unless the light-waves are
oriented at a specific angle to the lens.

Almost all LCDs (including PDAs, cell-phones, iPads, and even simple
displays like Cambridge *-NAV devices or digial variometers) have 1 or
2 polarized screens, as part of how they work. See he
http://en.wikipedia.org/wiki/Liquid-crystal_display

Stacking multiple polarizing filters in the proper orientation lets
light pass through. But stacking them in the wrong orientation causes
the light passing through the first filter to be BLOCKED by the
second.

Your polarized sunglasses _are_ a "second filter", sitting between
your eyeballs and the LCD screens in your cockpit. Ergo, if the
orientation of your sunglasses' polarized surface is not near the same
angle of your electronic displays, the visibility of your instruments
will be negatively impacted. Here are two video demonstrations of
this:
http://www.youtube.com/watch?v=GkLBMAY406Q
http://www.youtube.com/watch?v=HcQWAqL2JUw

Polarized sunglasses are not all manufactured the same; and even
different batches of the same sunglasses may not always have the
orientation to the polarized lenses - don't assume that because your
glasses work for you, that you can recommend them to others or that
you can simply buy another pair of the same, and have them work
identically. Additionally, just because you find glasses that may work
with _your_ cockpit instruments and canopy, do _not_ assume that it
will work with _all_ instruments or canopies. Finally, don't assume
that all of your instrument displays have the same polarization on
their screens. I have polarized lenses that work fine when viewing
some of my instruments, but not with others (unless you rotate the
glasses 90-degrees). Also, these polarized sunglasses worked fine
with my DG-300 canopy, but created horrible moire & checkerboard
patterns on a couple of Diamond DA-20 rental aircraft canopies.

If you're going to fly with a lot of cockpit electronics, I strongly
recommend against polarized lenses because you don't want to be
distracted or fumbling with your instruments because of this effect.
There are plenty of effective non-polarized sunglasses out there that
give you good visibility and protection.

Lastly, if you're going to be flying in a club or rental environment,
where you switch ships with any regularity, do NOT assume that
polarized sunglasses which work in one cockpit will work in another.

--Noel

All polycarbonate lenses block UV inherently. Acrylic plastic doen not unless treated. If the poly carbonate hald is treated then the UV blocking is enhanced. This is without tinting. Add tinting ro block visible light.
Any reasonable sunglasses will state the UV protection and almost any polycarbonate lens glasses will be over 95% whthout ocating or polarization.
Add polarazation if you want it. Filters to block the blue haze will help visibility.
Personally I have a set of 40 year old Ray Ban Aviators with another new set of lenses. Polycarbonate, tinted with Cryzal coating and I am delighted!
I liked then so much I ordered a new 3029 s and clear lenses mad exactly the samw with the caotings ets. Since they are Polycarbonate they will be over 95% UV blocking eventhough they are clear.