The best pilot sunglasses

[bleetman]

Glasses for aviators

I am a doctor, a pilot and a HEMS doctor. I have been aware for some tiime that very few optometrists understand the specific visual aid requirements for aviators. I have struggled to find someone to dispense glasses for the specific demands of flying (VMC, IMC, night, reading, intermediate range - instruments). I have encouraged an optician family member to think about this and he is opening a specialist optical outlet for aviators at Coventry Airport in January/February. He has recruited an optometrist who will conduct an enhanced examination on a flight deck which will fine-tune any optical prescription for night, IMC etc.

[alianablue]

I've read all the posts about sunglasses and it's all been real helpful thanks. I'm looking at buying a pair of Serengeti Velocity Drivers Gradient glasses and am wanting to buy them online from a company in the US($112 as opposed to £165.00 in Sunglasses Hut), but has anyone bought any recently and know how much VAT and Duty there is to pay?

[piggydog]

Serengeti's - a sunglasses problem

Hi there

A quick question on the old subject of sunglasses again: After reading loads of peoples thoughts and recommendations I settled for a pair of Serengeti Velocity Titanium with the sienna gradient lens.

I loved the glasses but today I tried them out in direct sunlight for the first time. My vision was completely disrupted by blue haze, from a couple of spots when looking towards the sun to patches covering the whole lens when at an angle from the sun. I wouldn't use these for walking in direct sunlight, never mind in the cockpit. The problem seems to be the blue coating on the inside of the lens that I haven't noticed on the glasses in the shops (I bought these on line from the US (so cheap!)).

Has anyone else had these problems? It seems strange that so many people recommended the glasses and they have such a positive recommendation.

Any replies much appreciated

Cheers

Piggy

[Wazzoo]

Photochromic sunglasses

I realise this topic has been done to death and there is a wealth of threads with peoples opinion on what the best sunglasses are, however I'm struggling to understand the restrictions specifically relating to photochromic lenses and subsequently which sunglasses I should go for.

Under HP&L the JAA say that photochromic lenses are generally forbidden due to the time taken for them to adjust to changes in light. Indeed, a number of threads on here quote Bad Medicine on the matter of sunglasses, specifically the bit that says:

Back to the original issue of photochromatic lenses. Photochromatic lenses have several disadvantages that render them unsuitable for use by pilots.

Firstly, their transition times are relatively slow. Photochromatic lenses take about five minutes to increase their density to the level of sunglasses, but more importantly, the bleaching time from maximum to minimum density can be as long as 30 minutes. Although there is a rapid lightening of the lens in the first five minutes, this may be too long when there is a sudden variation in light during a descent into or under cloud, or because of a rapid change in cloud cover.

Their second disadvantage is that, even when fully bleached, photochromic lenses still absorb slightly more light than untinted lenses. Since vision is critically dependent on ambient light levels, even this small decrease of light reaching the eye through photochromatic lenses is undesirable, especially at night or in low light levels. The inherent degradation of these lenses with time causes them to progressively become darker, as they become unable to reach the fully bleached state. This effectively prohibits their use in flying or controlling air traffic.

So theres me thinking it was a pretty much done and dusted matter that photochromic lenses were a no go for pilots. However in trying to work out what sunglasses to get, the ones from Serengeti have caught my eye. In fact, they've caught a lot of people's eyes from these forums and I reckon a good half of the posts on the matter swear by them. Add to that, most pilot supplies shops sell them and even found one web page saying they were part of the standard uniform for Delta pilots! (not sure if that last one is true or not).

But my dillemma comes from the fact that according to their website, all the Serengeti lenses are photochromic!

So..my question.. Has photochromic technology come far enough these days for it not to be a problem? Or is it that the Serengeti's only adjust from ~10%->25% in terms of light transmittance thus taking a relatively short time, and the issues surrounding photochromic lenses only really apply to lenses that go from completely clear to darkened? Alternatively, when the JAA says 'generally forbidden' it means its not a hard and fast rule and its up to you to make your mind up on what you feel comfortable with?

Any thoughts? Am I good to splash out on these, are am I going to end up with an expensive set of sunglasses I shouldn't be using half the time!

[Phone Wind]

Wazzoo,

The problem with photochromic lenses for flying is that many aircraft and helicopters have glass windscreens and these don't permit UV radiation (just the same as in a car, so they're no use for driving either). Photochromic lenses depend on a chemical reaction to the silver halide or silver chloride with which they are coated. These particles are transparent to visible light. However, when UV light strikes these particles, they change shape and absorb a proportion of the visible light which causes them to darken, the darkness being proportional to the intensity of the UV radiation. It's because of this that some photochromic lenses are pre-tinted so they can be used for driving. Naturally, that makes them near useless if you have to do any night flying.

The Serengetti Velocity gradient lenses are definitely not photochromic. I bought a pair just last month to replace an identical pair I've had for years and consider the best pilot sunglasses I've ever had. I also use Oakley Whiskers because the side arms mould closely to the temples and don't reduce the noise-cancelling properties of my ENC headset.

Piggy,

I fly in a country near the equator, so I wear them nearly every day and I've never had a problem you describe with a blue haze.

[Wazzoo]

Thanks for the reply Phone Wind.

Actually, what you said kinda answers my question but also kinda reinforces it because all Serengeti lenses are photochromic to some degree (just do a google search for Serengeti and photochromic, also mentions it on their website). When you say the Velocity gradient lenses I assume you mean the Velocity frames with Drivers Gradient lenses and according to the Serengeti web site they vary from 9% light transmittance to 24% light transmittance (for both the Drivers and Drivers Gradient), and the spiel at the bottom of the page says they adjust to the changing light.

http://www.serengeti-eyewear.com/tec...ns_drivers.cfm

However you say that by pretinting the photochromic lens they can be made suitable for driving/flying. Which I assume is the case with the Serengeti's in that they only go up to a maximum light transmittance of 24% (or less on other lenses). In which case they are not fully photochromic and are thus ok?

Am I making sense? Maybe I'm getting to techy with it and should just accept that they don't vary much so their ok to use...nuff said

(The Serengeti site also talks about the photochromic properties being impregnated during the firing process rather than using a silver alidade coating, so I wonder if this means they don't suffer from the problems you mention with the windscreens filtering UV)

[Bravo73]

Originally Posted by Wazzoo

In which case they are not fully photochromic and are thus ok?

That is absolutely correct. As far as I know, the JAA photocromic 'ban' is aimed at lenses that go from 'clear' to 'dark'.

Serengeti lenses only go from 'dark' to 'darker'.

Also, bear in mind the clear photocromic lenses will have some sort of focusing ability (whereas the majority of Serengeti lenses won't). Therefore, the user will need them to see and this might be restricted if they don't 'clear' quickly enough. If Serengetis are temporarily too dark, then the pilot can just remove them!

I fly with Serengeti Drivers Gradient lenses and basically use them in all conditions except at night. They are particularly good at improving contrast in flat light conditions.


HTH,

B73




PS Has anybody actually seen a reference to this JAA photocromic 'ban' outside of the HP&L textbooks? I can't remember seeing it in the ANO or AIP...

[Wazzoo]

Originally Posted by Bravo73

That is absolutely correct. As far as I know, the JAA photocromic 'ban' is aimed at lenses that go from 'clear' to 'dark'.

Serengeti lenses only go from 'dark' to 'darker'.
[...]
HTH,

B73

Helps a lot! Its what I suspected and what Phone Wind was getting at I think, but wasn't sure for certain that was the reasoning.

As for the what the JAA says on it...not much! Even the HP&L text book I have only says 'generally forbidden' and other articles (not from the JAA) I've read online say they are discouraged, but never seen anything to say they are completely banned or words to that effect.

[Wazzoo]

Not wishing to stir the proverbial nest but I did come across an article on sunglasses for pilots that might be an interesting read relating to the Serengetis. They don't say they are bad but there are things that people should be aware of when using them and for that matter other sunglasses.



http://www.aoa.org/x5349.xml

[Sierra Hotel]

Sunglasses

Hi all,
Have trawled through this thread attempting to work out which sunglasses would be best. I fly gliders and light aircraft, soon to go onto PPL, and hoping to go into aviation as a career (only 16). General consensus seems to be NOT Ray Bans. I like the look of the Aviators from Serengetti, but am yet to try them out. I have however tried some Oakleys with orange lense, which seem effective. So:
What would be best for general aviation. I'm looking for something to which will last me throught PPL and UAS for as long as possible, preferably in the classic aviator design. Do not need perscripted lenses of any kind.
Thanks
a somewhat confused Sam

[bleetman]

Sunglasses for aviators

Previously, I wrote about the new optical outlet for aviators at Coventry. I must declare an interest in this as I'm one of the directors. However, we put this together as no-one seems to be doing this for aviators. We have set up a facility to deal specifically with the visual requirements for pilots. We have built a flight deck on which we simulate all types of flying conditions as part of the eye examination (night, snow on the ground, IMC and bright VMC. This includes very bright conditions so that people can try out different types of sunglasses and see how each type measures up when confronted with a bright environment with different VMC conditions projected on a screen. Our customers can see how different lenses fare when trying to see little white gliders against a backdrop of clouds. The effect is really very good and helps people assess the efffectiveness of diffrent sunglasses in different glare conditions before they buy. We stock Serengeti, Oakley, Bolle and others. To clarify a few points - polarised lenses are discouraged, photochromic lenses are also discouraged. The military recommend neutral grey tints, helicopter pilots and many VFR pilots seem to prefer yellow tints as subjectively these provide better contrast definition. We're at Coventry Airport

[ZK-Brock]

Could someone recommend some reasonably inexpensive flying glasses? I'm a PPL student without much money to spend on such things. Would prefer something around no more than $75 US dollars.

[ILSTOMIN]

This may seem like a stupid question, but I am a little bit confused here.

Is photochromic lenses and polarized glasses the same thing?.
I'm looking to buy some glasses in the near future.

thanks.

[Phone Wind]

Yes, it's a stupid question. read the thread and go to Google to find the difference, then make sure you don't buy photocromic or polarised sunglasses for flying

[michaelthewannabe]

Oakley Crosshair - impressed

Thanks for the informative and useful thread.

After reading the thread and browsing the High Street, I found the Oakley Crosshair is quite excellent:

• huge unobstructed field of view
• arms with kinks to lie flat against the head, so comfortable underneath a headset
• usual Oakley optical quality and frame quality

I have a mild prescription - "spectacles advisable but not mandatory", it says on my Class 2 visual examination report. I got them with the plain grey (18% transmission) lens, and I'm very impressed. Good value at £240, too. I think they're about £140 without prescription lenses.

[Sheriftoma]

Sunglasses for Flying AND Driving!

Hi guys,
I wanted to see your opinion about which sunglasses you would all recommend for both flying and driving. I don't want to spend a million dollars on 2 pairs but I was looking at the VedaloHD sunglasses and they seem to work well for flying but Im not sure if they would have the same performance in the car (ie dark enough). Im willing to pay a good amount of money for them but I just wnat ones that would also not give me a headache (titanium would be ideal since my headset wouldn't push on them giving me a headache).
What do you all think?

Sherif

[D O Guerrero]

I think there's still a lot of useful information in this thread. But if you want my advice, I find the Seregetti Veolcities to be great in this respect (with brown drivers' lenses). I use them for driving and flying (with LCD screens) - what I particularly like is the comfort when they are on for long periods. The arms are flat so they don't feel awkward under your headset and they are super light, despite the glass lenses.
I've tried many different sunglasses - Rayban, Bloc, Oakley etc and none come close in my opinion.

[flyingdoc682]

As someone in the business of Aviation Medicine, Hawk's post is an excellent summary of the current recommendations. The original work was done by an Australian Opthalmologist, John Colvin, when he worked at NASA. The results of the studies are published in the journals Aerospace Medicine and Aviation Space and Environmental Medicine. Do a medline search.

Summary of specifications: Large thin titanium frames for field of view
Polycarbonate lenses
Neutral density Gray Green tint
15% transmission of light

[Asrian]

Hi,
I need to wear corrective glasses and am also looking for good sunglasses to wear when flying.

Question:
Can I get serengetis drivers gradient lenses with the right correction for my eyes or are they non-corrective lenses only?

In summer I'm going to London for a couple days. Is there an optician You can recommend, at Stansted airport or elsewhere in London, who stocks them and who has experience with pilots sunglasses?

[Checkboard]

I know some of this has been posted before, under other names, but as I wrot e the original, I thought I would copy the full text here.

Sunnies again! This has been on a few times over the board in various forums, here is a comment I have posted before, most recently in the "Questions" forum, under Serengeti sunglasses in the UK? (http://www.pprune.org/ubb/NonCGI/For...ML/001437.html)

There are several reasons to wear sunglasses. It is generally accepted that glare is harmful to the eye and that protection from glare is therefore therapeutic, even though studies show that only 22% of the population reacts adversely to glare. For these people the pupils are nearly pinpoints under such exposure. Diminished retinal luminescence cause measurable visual decrements and sunglasses will improve this visual acuity problem by counteracting the amount of available light. Conversely another 11% are at the opposite end of the sensitivity spectrum, these people actually have improved acuity under high glare conditions and seem to have no need for sunglasses.

It is not necessary to wear lenses inside the aircraft to protect a pilot from the injurious part of the UV spectrum, because canopy or cockpit windows will also block UV-B. (Acrylics, however, will not block UV effects and Ultra light or open-cockpit flyers will need sunnies.) UV-C is absorbed by the atmospheric ozone and is not supposed to reach the earth. Infrared rays (as in a heated cockpit) are not known to be a eye hazard.

Sunglasses are therefore essential for most pilots in order to cope with glare. The most important consideration for sunglasses is that they reduce glare without affecting vision. Lenses should not be too dark and the standards given for pilots is that they transmit at least 15 per cent of incident light. The tint must be "Neutral density" (ND) which means that it doesn't affect colour perception. The recommended tint for aviation sunglasses is therefore ND15. (This is the US military specification standard for aviators sunglasses and tinted visors, and may have its scientific origins in a 'best guess scenario' more than fifty years ago.) Only sunglasses that conform to the Australian standards should be worn . Those marked "specific purpose sunglasses" are recommended.

Pilots who wear prescription sunglasses may either wear clip-on lenses or they can get their prescription sunglasses made with ND15 lenses. Clip-ons have the advantage of being easy to remove when there is a quick change from light to dark conditions.

If you chose to have your prescription lens made with a tint then it is essential to have another pair of untinted lenses for night and low glare flying. Pilots who wear look-overs are advised to use bifocals instead and then wear clip-ons.

There are two main materials, crown glass and a plastic known as CR39. A very tough poly carbonate lens material is also available. All three lens materials are acceptable. CR39 and polycarbonate have these advantages : highly impact resistant; light weight; and low thermal conductivity and thus less liable to fogging.

CR39 is more vulnerable to surface damage than glass and CR39 lenses must be carefully protected from scratching. CR39 can be obtained with an abrasion-resistant coating to reduce its susceptibility to surface damage.

Polaroid lenses should be left in your boat. (Everybody has one right ) Their chief attribute is that quality Polaroid lenses will completely eliminate glare coming from a flat surface that is of an angle of approximately 53%. A pilot wearing Polaroid lenses sees the world as constantly changing according to his (or her) angle of bank, as the angle of the glare is altered.

Liquid crystal displays work by electrically controlling filtered polarised light, the crystal is orientated by electric current, so as to polarised light to either pass through or be blocked by a polarised filter. All light emitted from LCD screens is therefore polarised, and cannot penetrate a polarised lens if that lens is orientated 90 degrees to the light - so any LCD may appear blank with polarised lenses on, and looking through a polarised window can result in no view at all!

Lens colors are seen in different ways: Green or grey are said to give the least color distortion, and are available in combination. Yellow has the capability of filtering reflected short-wave blue which is found in air contaminants such as fog, haze, smoke or smog. In certain conditions therefore yellow "blue blockers" can improve visual acuity, but not because they protect from glare. Yellow lenses that cut out more than 30% of ambient light can affect color perception and military pilots complain that depth perception is altered. Brown, if it is not too dark, will enhance contrast as well as doing a modicum of blue-blocking. Rose also increases contrast and blue-blocking offering a niche in car use.

In summary, aviators' sunglasses should: be glass or polycarbonate; transmit not less than 25% of available light; not distort colors, distances or shapes; nullify the blurring effect of short-wave reflected blue; have their adverse effect on visual acuity well understood; and not be worn under conditions of diminished light.

As an aside, I bought a pair of glass Serengettis with a brown tint for nearly $AUD300. I didn't like the weight of the glass lens at all, and the brown tint, while it was good for glare, made the green information on EFIS a little hard to see when I transistioned to EFIS. In addition the inside of the lens was highly relfective, so as I was sitting in shadow (in the cockpit) looking out at a bright field (like a cloud deck from above) they gave me a perfect image of my eyes looking back at me (reflected from the inside of the lens). That was difficult to ignore. I now fly with a pair of $AUD15 plastic sunnies I bought from a Chemist and I am much happier with them.

In Australia pilots may claim one pair of sunnies per year at tax time.

sources:
-CAA (Australia) Aviation Safety Digest (ASD) 150 (1991)
-ASD 136 (Autumn 1998)
-ASD 133
-CASA's Flight Safety Australia (Sept. 1997)

Copies of all of these articles are available for free if you contact (Australia'a CASA or BASI)