Polarized lenses for night driving?

[Quince]

http://www.allaboutvision.com/sunglasses/polarized.htm

This has some good key points:

"These sunglasses can be used for driving and, in fact, can reduce glare from a long, flat surface such as the hood of the car or the road's surface." (Speaking about polarized sunglasses for daytime use. So why not clear polar at night?)

"Light reflected from surfaces such as a flat road or smooth water generally is horizontally polarized. "

"And polarized photochromic lenses, which change from dark outside to light inside, may be right for the light-sensitive person who frequently is in and out of the sun on any given day."

[Uilleann]

Why does the link in your post lead to an automotive parts supplier?

Its an autolinking robot. Not placed by me. You'll have to ask Steve what that's all about I suppose, though I doubt he has any control over it either.

http://www.allaboutvision.com/sunglasses/polarized.htm

This has some good key points:

"These sunglasses can be used for driving and, in fact, can reduce glare from a long, flat surface such as the hood of the car or the road's surface." (Speaking about polarized sunglasses for daytime use. So why not clear polar at night?)

"Light reflected from surfaces such as a flat road or smooth water generally is horizontally polarized. "

"And polarized photochromic lenses, which change from dark outside to light inside, may be right for the light-sensitive person who frequently is in and out of the sun on any given day."

There is no such thing as a "clear polarized" ophthalmic lens. In order to function, polarized ophthalmic lenses require tint. The more tint, the higher the polarizing efficiency. Your link refers ONLY to daytime driving conditions with full sun. NOT night driving. Further, the light reflected from a road surface, or the hood of a car may well be polarized, however, at night, that is not a major source of glare. Direct headlight glare is the #1 complaint when driving at night. That is NOT mitigated by polarization, or tint. Transitions Vantage - your above referenced "polarized photochromic lens", will not be activated at night, and will therefore remain non polarized. In addition, the residual tint of that type of lens may further degrade contrast sensitivity at night.

How long have you been a tech Quince? This is all rather basic knowledge. Perhaps others here might suggest some good reading material concerning the polarization of light, and how the eye functions under photopic, mesopic, and scotopic visual conditions, and how visual acuity and contrast sensitivity is affected at night. Hope that's helpful at any rate.

[AngeHamm]

The Vantage will also not activate during the day behind your windshield. It will offer you absolutely no driving benefit at any time unless you drive a convertible.

[Uilleann]

The Vantage will also not activate during the day behind your windshield. It will offer you absolutely no driving benefit at any time unless you drive a convertible.

Agreed. In addition, even at it's best, that lens was found to be only something like 65% efficient in its fully activated polar state. Not so hot any way it's sliced.

[Robert Martellaro]

Zeiss's solution.

http://www.zeiss.com/vision-care/en_...scription.html

http://64.50.176.246/files/wavefront...cle_lenses.pdf

The Eye and Night Vision

http://www.valleyflyers.org/wp-conte...ightVision.pdf

[drk]

Uilleann is right, as usual. He's just lucky that way.

Why on God's green earth would we use polarized lenses at night? What light source is polarized? Headlight reflections off of puddles in the road?

Or is it that, somehow, plane-polarized light "scatters" less in the ocular media? Nope.

Even if it did, you'd have to put up with contrast sensitivity reduction...LIKE THAT DEER IN YOUR HEADLIGHTS! LOOK OUT!!!!

Yeah, G15 lenses are great when looking down the barrel of two halogen Mercedes high beams (like Chris Ryser's). But you just killed the teenage runaway skateboarding after dark on the shoulder. His mommy will never see him again. And it's your fault for not knowing optics worth a darn.

[drk]

Agreed. In addition, even at it's best, that lens was found to be only something like 65% efficient in its fully activated polar state. Not so hot any way it's sliced.

Hey, it's POLARIZED. Didn't you get the memo? It's P-O-L-A-R-I-Z-E-D. "Woo-hoo, honey, my TransAm's are polarized. Let me do the drivin' again."

[drk]

Zeiss's solution.

http://www.zeiss.com/vision-care/en_...scription.html

http://64.50.176.246/files/wavefront...cle_lenses.pdf

The Eye and Night Vision

http://www.valleyflyers.org/wp-conte...ightVision.pdf

First, that Valleyflyers thing from the AOA is fascinating.

Second, I think Zeiss is full of hooey.

What if the patient is refracted in dim illumination? I do that, generally. Or if they're dilated while refracted? I sometimes do that. They are basing their "paradigm" on their glasses being better because of wavefront? They still can't deliver higher-order-aberration control, but they don't mention that little concern.

Otherwise, if they want to say that a bigger pupil gives positive spherical aberration (I think the average is about a quarter diopter at most) then they can call Barry Santini for his "extra sauce" recipe. Whoop de do.

And don't even begin with that "digital surfacing matters" stuff. At least, not in the central optics.

Bad Zeiss. Bad, bad Zeiss.

[drk]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3666881/

Good readin'. Let's do a book report together.

[optical24/7]

Doc, have you been hanging out with Chip Anderson again?

[Quince]

Wow, heated....

Anyways I did specify the article was talking about daytime driving and I also specified that the idea of using Vantage was for night only. It would not be nearly dark enough during the day for me either way. I thought this was a place to bounce ideas around? Huh...

I was also under the impression that the polarized filter doesn't 'go away' or is ever inactive. I'm unclear here and would love clarification.

I will certainly look into the links Robert posted and appreciate actual resources.


As for my credentials- should you deem them necessary- includes 5 years of self teaching and support from co-workers with much more experience than I. I am in an unlicensed state where they throw you to the wolves and if you survive with only on the job training than you tend to stay in the field. I hope that helps you understand the position of learning I am in and maybe why I'm here. To learn. Thanks for the feedback

[drk]

Lesson One:

Tints are pigments that absorb light.

No tint, no absorption.



Lesson 2:
Polarized filters are pigments that are arranged (somehow) like slats on a blind (or something) that blocks, say, half of the reflections. But you still need a tint. They're light, because they are only about half-tinted. Sorta.

The real explanation is that light waves (theoretical constructs) vibrate in all directions. Think of jerking on a jump rope tied to 24/7's neck. You can make it oscillate horizontally, vertically, obliquely, actually in all directions (until 24/7 turns blue and passes out). That is how light vibrates. All at once.

Now once light hits a (shiny) surface, the REFLECTION is polarized. Only the light that was vibrating in the direction of the incident angle is reflected, the rest is absorbed. If you orient your filter 90 degrees to this, the "slats" absorb it and block it out. But you need tint. Transparent blinds do a crappy job. Like the VSP labs.

[optical24/7]

Think of jerking on a jump rope tied to 24/7's neck. You can make it oscillate horizontally, vertically, obliquely, actually in all directions (until 24/7 turns blue and passes out). That is how light vibrates. All at once.

.

You've not seen my extremely muscular neck? A bulldog has more neck than me!

[Don Gilman]

Lesson One:

Tints are pigments that absorb light.

No tint, no absorption.



Lesson 2:
Polarized filters are pigments that are arranged (somehow) like slats on a blind (or something) that blocks, say, half of the reflections. But you still need a tint. They're light, because they are only about half-tinted. Sorta.

The real explanation is that light waves (theoretical constructs) vibrate in all directions. Think of jerking on a jump rope tied to 24/7's neck. You can make it oscillate horizontally, vertically, obliquely, actually in all directions (until 24/7 turns blue and passes out). That is how light vibrates. All at once.

Now once light hits a (shiny) surface, the REFLECTION is polarized. Only the light that was vibrating in the direction of the incident angle is reflected, the rest is absorbed. If you orient your filter 90 degrees to this, the "slats" absorb it and block it out. But you need tint. Transparent blinds do a crappy job. Like the VSP labs.

Whoooo! Dander up. I LOVE IT, KEEP IT UP.

[Quince]

Lesson One:

Tints are pigments that absorb light.

No tint, no absorption.



Lesson 2:
Polarized filters are pigments that are arranged (somehow) like slats on a blind (or something) that blocks, say, half of the reflections. But you still need a tint. They're light, because they are only about half-tinted. Sorta.

The real explanation is that light waves (theoretical constructs) vibrate in all directions. Think of jerking on a jump rope tied to 24/7's neck. You can make it oscillate horizontally, vertically, obliquely, actually in all directions (until 24/7 turns blue and passes out). That is how light vibrates. All at once.

Now once light hits a (shiny) surface, the REFLECTION is polarized. Only the light that was vibrating in the direction of the incident angle is reflected, the rest is absorbed. If you orient your filter 90 degrees to this, the "slats" absorb it and block it out. But you need tint. Transparent blinds do a crappy job. Like the VSP labs.

I've heard about the slat formation but didn't realize it needed the tint to be effective. Your explanation was informative AND comical. That's how I learn best!!

So we make polarized lenses 90 degrees off to counter that polarized light- does that mean that all polarized light is traveling at the same angle?

[Uilleann]

Wow, heated....

Anyways I did specify the article was talking about daytime driving and I also specified that the idea of using Vantage was for night only. It would not be nearly dark enough during the day for me either way. I thought this was a place to bounce ideas around? Huh...

I was also under the impression that the polarized filter doesn't 'go away' or is ever inactive. I'm unclear here and would love clarification.

I will certainly look into the links Robert posted and appreciate actual resources.

As for my credentials- should you deem them necessary- includes 5 years of self teaching and support from co-workers with much more experience than I. I am in an unlicensed state where they throw you to the wolves and if you survive with only on the job training than you tend to stay in the field. I hope that helps you understand the position of learning I am in and maybe why I'm here. To learn. Thanks for the feedback

You bounced - we bounced back. All part of the learning process eh? :) You're asking questions - which is the most important thing you can do. Followed immediately, of course, by listening to the information you get from asking. I asked if you were new as we were ALL new at this game once upon a time. Some of us with rather more time than others! I've only got about three decades in the ring myself, and am always learning new things. Keep ravenously asking questions like these, and taking the answers to heart, and you'll do just fine - license be damned.

As for the Vantage lenses at night - nope, not gonna work. Without the tint, there is no polarization. And again, the illumination we experience at night is not the same as under daylight. Even the very best polar lenses, under the brightest sun, only remove a small portion of reflected horizontal glare. The majority of the 'work' of any sun lens is in the overall reduction of light intensity (not just polarized rays) across the visible spectrum (accepting of course the variations between different base tint colors, and of course mirrors if present). Polar lenses are very nice, but the effect is much more subtle than overt in 95% of daylight scenarios.

It sounds seriously silly...but the best thing 99% of drivers at night can do is clean the inside of your car's glass. Get rid of the film, and watch your night glare from point light sources drop off a cliff. Cleaning the outside is important too of course, but the insides of the majority of windscreens are filthy. I can confirm this with even new cars, as well as used and abused cars after detailing them for a good number of years.

You know that green nose cheese you pull off nose pads and arms? I've seen even worse come off the inside of auto glass.

[Chris Ryser]

Uilleann is right down to the point.

[Paul Smith LDO]

You bounced - we bounced back. All part of the learning process eh? :) You're asking questions - which is the most important thing you can do. Followed immediately, of course, by listening to the information you get from asking. I asked if you were new as we were ALL new at this game once upon a time. Some of us with rather more time than others! I've only got about three decades in the ring myself, and am always learning new things. Keep ravenously asking questions like these, and taking the answers to heart, and you'll do just fine - license be damned.

As for the Vantage lenses at night - nope, not gonna work. Without the tint, there is no polarization. And again, the illumination we experience at night is not the same as under daylight. Even the very best polar lenses, under the brightest sun, only remove a small portion of reflected horizontal glare. The majority of the 'work' of any sun lens is in the overall reduction of light intensity (not just polarized rays) across the visible spectrum (accepting of course the variations between different base tint colors, and of course mirrors if present). Polar lenses are very nice, but the effect is much more subtle than overt in 95% of daylight scenarios.

It sounds seriously silly...but the best thing 99% of drivers at night can do is clean the inside of your car's glass. Get rid of the film, and watch your night glare from point light sources drop off a cliff. Cleaning the outside is important too of course, but the insides of the majority of windscreens are filthy. I can confirm this with even new cars, as well as used and abused cars after detailing them for a good number of years.

You know that green nose cheese you pull off nose pads and arms? I've seen even worse come off the inside of auto glass.

Brian, some of us cover our face with our hands when we sneeze while driving. It's the passenger seat you got to be worried about. Hey, that's not a fleece seat cover your sitting in.

[Chris Ryser]

Uilleann is right, as usual. He's just lucky that way.

Why on God's green earth would we use polarized lenses at night? What light source is polarized? Headlight reflections off of puddles in the road?

................................

Yeah, G15 lenses are great when looking down the barrel of two halogen Mercedes high beams (like Chris Ryser's).

Yes Villeann is right, and you drk, is nearly right, but a bit off key.

No Mercedes.
I own 2 "Town & Countries" and have an old Cady SRX, 2006 in my garage in Naples, FL with now 31,000 miles on the clicker.(still looks like new inside out).

Besides that G15 lenses absorb over 70% of visible light, you would not use them at night on a highway with tons of barrels of halogen lights on Mercedes or other cars coming at you.

When still working for fathers store in Switzerland years ago, we used to sell yellow lenses with a 10 mm square mirrors, just de-centered, so you could move your head and deflect those bothering headlights, and there was no halogen lights then.

[Quince]

You bounced - we bounced back. All part of the learning process eh? :) You're asking questions - which is the most important thing you can do. Followed immediately, of course, by listening to the information you get from asking. I asked if you were new as we were ALL new at this game once upon a time. Some of us with rather more time than others! I've only got about three decades in the ring myself, and am always learning new things. Keep ravenously asking questions like these, and taking the answers to heart, and you'll do just fine - license be damned.

As for the Vantage lenses at night - nope, not gonna work. Without the tint, there is no polarization. And again, the illumination we experience at night is not the same as under daylight. Even the very best polar lenses, under the brightest sun, only remove a small portion of reflected horizontal glare. The majority of the 'work' of any sun lens is in the overall reduction of light intensity (not just polarized rays) across the visible spectrum (accepting of course the variations between different base tint colors, and of course mirrors if present). Polar lenses are very nice, but the effect is much more subtle than overt in 95% of daylight scenarios.

It sounds seriously silly...but the best thing 99% of drivers at night can do is clean the inside of your car's glass. Get rid of the film, and watch your night glare from point light sources drop off a cliff. Cleaning the outside is important too of course, but the insides of the majority of windscreens are filthy. I can confirm this with even new cars, as well as used and abused cars after detailing them for a good number of years.

You know that green nose cheese you pull off nose pads and arms? I've seen even worse come off the inside of auto glass.

I'm ALWAYS asking questions! That's actually why I switched to the lab from being hired for retail. The science and ever changing tech is the best part... well, besides buying frames.

And you are right about the windshield. I've had to replace mine twice on a car three years old. Everytime, I see it as a blessing in disguise because of the clarity. I recently cleaned mine, but then decided anti-fog spray would be a good idea. Sure keeps the glass defogged, but also mucks up my once streak free shine. Sometimes you can't have the best of both worlds.

[Uilleann]

I'm ALWAYS asking questions! That's actually why I switched to the lab from being hired for retail. The science and ever changing tech is the best part... well, besides buying frames.

And you are right about the windshield. I've had to replace mine twice on a car three years old. Everytime, I see it as a blessing in disguise because of the clarity. I recently cleaned mine, but then decided anti-fog spray would be a good idea. Sure keeps the glass defogged, but also mucks up my once streak free shine. Sometimes you can't have the best of both worlds.

Yes, the glass is often a major culprit of glare. Autos are very bad more often than not - and you're right as well that many of the anti-fog treatments do leave a residue or film on the glass. No fog, but the trade off is likely more glare. Aircraft windscreens are tricky as well, and while many of them don't have the same film build up inside, fogging can be an issue. And of course there's all the bugs, birds, and martians you have to keep scraping off the outside that make for an *exciting* time shooting short finals at night! :)

There is also the other glass to consider...the eyeglass. Just like the car, we all know that the majority of the glasses we see come across our desks are filthy, scratched, covered in paint, hair spray, bodily fluids, mystery sauces...its a wonder some people see at all! Cleaning of all optical surfaces is the best first line of defense to combat glare at night. After that, a high quality anti glare lens. And of course, regular annual visits to the eye doc to maintain optimal comprehensive ocular health.