Polarized Sunglass Lenses in GA

[flybyfire]

In commercial aviation it's advised not to wear polarized lenses for various reasons, but in general aviation; is it ok to have a polarized lens in your sunglasses for flying in PA28s/152s etc?

Ta

:cool:

[caber0]

Really not a good idea as polarising light shows up rainbow like fringing in stress areas of perspex and toughened glass pretty much what you are looking through so really not good for visibility.

Caber:(

[xj8driver]

I had polarised prescription shades, and they were no good at all - they badly affected depth of field, and judging distance became very difficult. Best avoided in my opinion.

[RTN11]

The main problem is that the screen on certain radios and GPS displays are also polarised. If it just happens that they are polarised the opposite way to your glasses, you will not see anything displayed on the screen unless you rotate your head through 90 degrees. In airlines with glass cockpit, the whole instrument panel is a polarised screen so not being able to see this would be a big concern

So if you fly some microlight or old school aircraft with old radios, or no radio at all, you'll probably be fine.

If you intend to use GPS, or any radio nav aids there's a chance you'll have a problem.

Also the psycedelic rainbow colours as mentioned above. It's what I'd imagine being on LSD is like :}

[maehhh]

I mostly fly with Ray Ban polarised lenses and never had any trouble... not even rainbows somewhere!

Handheld Garmin GPS - no problem
Garmin 430/530 - no problem
Garmin G1000 - no problem
Same for all Bendix/King radios or displays so far

I remember one Shadin fuel flow indicator in a TB20 which was hard to read but that was not a big issue... :ok:

On a sidenote:
I remember the Australian Visual Flight Guide recommending polarised lenses for GA pilots to discover "dust devils" earlier!



Cheers
maehhh

[S-Works]

I have been usng Maui Jim polarised sunglasses for over 4,000hrs and never had a problem.....

They are great for penetrating haze.

[Zulu Alpha]

Try looking at an LCD screen with polarised glasses. If you can see it then rotate the screen or your glasses 90 degrees and it will disappear.

So Polarised glasses are OK as long as the manufacturers of your avionics have all aligned their screens in the right way for your glasses.

[piperarcher]

Try looking at an LCD screen with polarised glasses. If you can see it then rotate the screen or your glasses 90 degrees and it will disappear.

A good example of this is an iPad. I was in the right hand seat while my flying partner was P1 in our PA28. I took my new iPad up with me to try out a few of the moving map prodcts and to test the GPS reliability. I had my polarised sunglasses on and I seriously thought the iPad had broken on me. I switched it off / on, hard re-booted it and did everything I could to make it work. Then I took my polarised glasses off, and voila, iPad is working after all :) . I must admit I never had any other issues. No depth issues, and things seems fine in low vis, in and and above cloud too.

[Ds3]

Interesting topic. I'm aware of the issues polarised lenses can cause when viewing other polarised screens (can't see petrol pump displays for instance) however haven't encountered any issues in my Robin yet so am happy enough using my Oakleys. I've not had any 'rainbow' effects either.

I'm surprised about the depth of field issues mentioned though, certainly not something I've experienced and I wasn't aware this was a potential issue with polarised lenses.

[24Carrot]

The polarisation is there to stop you being "blinded" by reflections off water e.g. by the pool or on the beach.

When flying over land you don't need to worry about this glare, but you do want to see reflections off lakes, rivers, etc, which can help your navigation.

[S-Works]

When flying over land you don't need to worry about this glare, but you do want to see reflections off lakes, rivers, etc, which can help your navigation.

Whats up with a GPS......

I fly commercially and wear polarised sunglasses..... :ok:

[peterh337]

Polarised glasses mess up most avionics (LCD) displays.

They are good for flying over water though. But I don't fly with them because they are useless in a modern cockpit.

Polarising filters are super on cameras :) You get great colours (http://i101.photobucket.com/albums/m74/peterh337/kithira1.jpg) and no glare without any retouching, and anyway glare cannot be retouched (practically).

[riverrock83]

Generally, how LCD displays work is that a back light (or could be ambient light from in front) is passed through a polarisation filter. Then there are segments of a specialised liquid crystal which polarises light when an electrical charge is passed through it. This is aligned 90deg to the first filter. Therefore when power is applied to the segment, it will block the light.
This means that light from LCDs will be polarised one way.

There are a lot of variables as to whether glasses will be effected. The screens are only blocked if the polarisation is at 90degs to the polarisation of your glasses.

Most glasses are polarised vertically because water glare is mostly horizontal. LCD manufacturers know this so tend to polarise the light vertically so will work with most sun glasses. However there are a fair number of examples where this is different (some the other way round, others at 45deg, some circularly polarised). It means that if you tilt your head the screen will get darker. There are other ways round this but they are more expensive.

I don't have an iPad so I don't know which way the screen is polarised, but from the odd online link, it suggests it will work in landscape for most people with polarised sunglasses but not in portrait.

Personally - I don't want to risk not being able to see something if my glasses slip, so I've got non-polarised sun glasses.

[Pilot.Lyons]

I use ray ban polarised glasses and allways have... Not ever experienced anything affecting my vision... I think they are brilliant

[RTN11]

You all must fly some very well kept aircraft.

Fly in a typical club trainer or microlight with polarised lenses, and any cracks or stresses in the perspex screen turn into a rainbow. Very pretty, and certainly good fun, but not really helping a good lookout.

In terms of radios, I've only ever had problems with two, one was in a C42 microlight, the other was a bendix king DME. Strange it only seemed to be that unit since I've never had problems with others.

[B2N2]

What an utter rubbish in this thread:

When flying over land you don't need to worry about this glare, but you do want to see reflections off lakes, rivers, etc, which can help your navigation

they badly affected depth of field, and judging distance became very difficult

This seems to a persistent myth that simply does not want to die.
Yes I know how polarization works and I know that I can "autodim" a G430 display by turning my head but do you really look at a display with your head sideways? Really?:ugh:
Same as Bose-x, I have my last 4000 hrs behind polarized glasses; Ray-ban,Maui Jim and el-cheapo wal-mart "fishing" glasses and I wouldn't fly without polarized anymore.

[24Carrot]

This seems to a persistent myth that simply does not want to die.

As you have a US location, you are very well placed to tell the FAA to stop pushing this myth.

http://www.faa.gov/pilots/safety/pilotsafetybrochures/media/sunglasses.pdf

[chrisbl]

The CAA have a similar view too

Guidance on using sunglasses | Medical | Safety Regulation (http://www.caa.co.uk/default.aspx?catid=49&pagetype=90&pageid=9244)

[englishal]

Never had a problem and have worn them for many hours.

Yes, if you rotate your head 90 degrees then the G1000 screen will go dark....but it is no biggie and it is not often you lay down for a nap when flying.

[B2N2]

24 carrot ;

POLARIZATION. Polarized lenses are not recommended
for use in the aviation environment. While useful for blocking
reflected light from horizontal surfaces such as water or
snow, polarization can reduce or eliminate the visibility of
instruments that incorporate anti-glare filters. Polarized lenses
may also interfere with visibility through an aircraft windscreen
by enhancing striations in laminated materials and mask the
sparkle of light that reflects off shiny surfaces such as another
aircraft’s wing or windscreen, which can reduce the time a pilot
has to react in a “see-and-avoid” traffic situation.

I read it as regular sunglasses will NEVER cause interference (by their design) and polarized MAY ( not a garantee) do so in combination with certain instruments.
So in certain aircraft you MAY and in other aircraft you MAY NOT encounter issues.
For clarification; I fly G1000 equipped Diamond aircraft with a curved perspex canopy and have NEVER encountered problems doing so.
Flying your average spam-can will not be a problem with polarized sunglasses.
An average spam-can is not a business jet with 8 different layers of various different materials inlcuding heating pads for a wind screen.

So some may and some may not.:suspect:
To generally state that polarized is a no-no in aviation is an urban myth that has roared its ugly head at least a dozen times in the last 10 years here on PPrune.

As stated earlier I currently wear a Walmart brand polarized pair of shades from the fishing department and I have had zero issues picking out traffic in a wide spread of atmospheric conditions.:ok:

It belongs in the same list of aviation myths as the following:


I need a Ray Ban Aviator to be taken seriously at my club
I need a Breitling to be taken seriously at my club
I need to wear a army/navy/airforce issue poop-suit to be taken seriously as a PPL
I need to wear epaulets on a cross country so the locals know I am a PPL holder

[riverrock83]

24 carrot ;
It belongs in the same list of aviation myths as the following:


I need a Ray Ban Aviator to be taken seriously at my club
I need a Breitling to be taken seriously at my club
I need to wear a army/navy/airforce issue poop-suit to be taken seriously as a PPL
I need to wear epaulets on a cross country so the locals know I am a PPL holder



I must disagree, since there is a logical and well thought through position from officialdom (as previously linked to) it can't be in the list above.

Whether its correct or not is potentially open to debate as there doesn't seem to be much in the way of scientific evidence either way.

How do you know you wouldn't have seen another aircraft a few seconds sooner if you didn't have your Walmart specials on? One thing I've noticed is that there is a loss of clarity when viewing through some cheap pairs of glasses - so I wouldn't go bargain basement. You need optical quality glass / plastic. Keeping glasses grease free can also make a huge difference. There is also a question of the amount of light coming in around the edges of the glasses. Lots and you will get glare and (over time) eye strain.

And most importantly - you can't put an iPad the way you want it :ok: