Question About Polarization in My Sunglasses

Use cocaine. It will contract your pupils so much that you won't notice these almost invisible areas.

You must have an experience like this before Tornado. I bet.

Looks like stress warp, but also could be a trick of polarization interacting with the LED display...

I took another photo of it in front of a blank white piece of paper, but with my dslr and polarizing filter on my lens and it gave the same results, so LED display was ruled out as the cause.
But indeed, it does look like stress warps. Is this common with polarized glasses?

The polarization of lenses is highly angular in nature, so using 2 polarized lenses together with yield different results depending on the angle of the light striking the lenses and the orientation of each lens to the other...the bending of a polarized lens then alters the angle of the light with reference to the lens resulting in a variance of effectiveness of light blocking ability...

http://www.polarization.com/water/water.html

Stress warp, probably polarization treatment was given while the glasses were not bent. Bending it to fit the frame consequence such as this.

It may be circular polarized not linear. If you try the same 3D glasses, used for 3D movies, you should get the same results. i have been doing some experiments on linear polarization of a line laser attempting to reduce laser speckle for use on laser triangulation sensors.

Not that it matters greatly but, the stress lines seen in your example and in the plastic eating utensils and in the other in Wiki photo are molded in stresses resulting from the injection molding process used to make them.

The OP's example, I believe, is caused by post molding stresses induced by the frame.

Not sure it worth popping the lenses out of the frame to find out.

Oh wow this is all very interesting! Is this found often among sunglass makers? Is this something standard that people normally don't notice?

Is this something standard that people normally don't notice?

Of course. Most people do not know the mechanics of polarization. I tell everyone to test their polarized sunglasses by looking thru 2 sets of glasses and rotating one set 90 degrees. You should get a total dark and not be able to see thru the lenses when rotated.

Are these stress marks common in sunglass manufacturing?

When I was young lad, my dad, who was a smoker, took the cellophane off the cigarette package and put it between two polarizers to show me the colors. I've been hooked every since.

https://www.google.com/search?q=cellophane+tape+polarized+light&espv=2&biw=1264&bih=571&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMInfqf3r7ixgIVjAuSCh1uFAIp#imgrc=_

I see a surgeon in action, on someones skull... 's cool !!!

I'm a bit more interested in the 2nd stage of Falcon and what caused its failure. your defective glasses very quickly put me into a coma

I find both this post and your space postings interesting.

Good blog.

It sounds as though we should "check" such glasses before buying them.....

The only time (many years ago) that I had two pairs of Polaroid sunglasses in my hands to test together, both went black with no fringing as shown in these (excellent) pictures.

These here appear to have been badly made, but am I wrong to say that??? Do they still do the job well?

It depends on the quality of sunglasses you are purchasing.I had tried purchasing sunglasses online you can check online which will help you to compare the cost and product to.

You want a pair of good "blue blockers" dark glasses cause the pupils to dilate and since dark does not control sufficiently the UV you can have eye damage. Blue blockers as the name claims controls the UV (blue) spectrum providing a crisper image with out the pupils dilating to compensate for the darker lens. Any way this is how it was explained to me by a military eye specialist.

Makes sense.

I believe the issue here is the manufacture of the actual lens and the type of polarizing film technology used. Sure they all claim they are polarized, but note that the polarizing film location determines the quality and hence the price tag. Cheaper polarizing techniques place the polarization film either on the front or the back of the lens (usually the back - as in your case). More expensive, durable and optically clearer polarizing will be in between two 'plates' of tinted lens.

There are typically three types of manufacture processes: Vacuum Forming, Injection Molding and Press Polish forming as explained here. I would guess from your pictures it would be vacuum formed.

Hi there, according to me this has happened because the quality of your sunglass was not good. As I had also bought a pair of polarized sunglasses and I have not faced such things. I have bought it from an online store where they offer best deals on sunglasses with a high quality. If you buy your sunglasses from the right place, then you will not face such problem.