NoBozo
08-20-2012, 06:35 PM
I just bought a new pair of "Polarized' sunglasses from my local CVS.
When I was in the Navy a long time ago I worked with optics...submarine periscopes..binoculars..etc (lenses). I also learned about "Polarized" lenses. They were invented by the Polaroid Company.
Polarized lenses cut down "Reflected Light" entering your eyes. This is GOOD. I won't get into describing HOW they work but just describe how you can TELL IF the sunglasses you are considering buying are actually "Polarized".
Pick up the sunglasses in question and hold them maybe a foot or so away from your face...and look through them...THIS is MOST important... at a surface in the store..between you and outside light.....a reflection off of maybe a counter...or a product on a shelf.
Sometimes it is difficult to find a good reflecting surface in the store..but look around the store...looking toward natural light. (the front of the store) SO: LOOK through one side of the sunglass lenses in the normal horizontal position that the glasses will be on your head... THEN ROTATE the glasses 90 degrees..ie to vertical. The reflection "should" come back IF the lenses are trully "Polarized". Do this a few times to SEE the difference when you rotate the glasses 90 degrees while looking at a reflected light. Polarized lenses CANCEL reflections.
Most of the glasses on the rack have minimal or NO polarizing effect...regardless of what the advertizing says. When the glasses are verticle...the polarising effect will be minimul. When the glasses are horizontal..as on your head..the reflection cancelling effect shoud be at Maximum.
SO: When you are walking through your local drugstore..stop by the sunglass kiosk and pick up a pair of "Polarized' sunglasses and try what I have described above.
ROTATE the sunglass 90 degrees ..while looking at a reflection..and see the change. :look: NB
When I was in the Navy a long time ago I worked with optics...submarine periscopes..binoculars..etc (lenses). I also learned about "Polarized" lenses. They were invented by the Polaroid Company.
Polarized lenses cut down "Reflected Light" entering your eyes. This is GOOD. I won't get into describing HOW they work but just describe how you can TELL IF the sunglasses you are considering buying are actually "Polarized".
Pick up the sunglasses in question and hold them maybe a foot or so away from your face...and look through them...THIS is MOST important... at a surface in the store..between you and outside light.....a reflection off of maybe a counter...or a product on a shelf.
Sometimes it is difficult to find a good reflecting surface in the store..but look around the store...looking toward natural light. (the front of the store) SO: LOOK through one side of the sunglass lenses in the normal horizontal position that the glasses will be on your head... THEN ROTATE the glasses 90 degrees..ie to vertical. The reflection "should" come back IF the lenses are trully "Polarized". Do this a few times to SEE the difference when you rotate the glasses 90 degrees while looking at a reflected light. Polarized lenses CANCEL reflections.
Most of the glasses on the rack have minimal or NO polarizing effect...regardless of what the advertizing says. When the glasses are verticle...the polarising effect will be minimul. When the glasses are horizontal..as on your head..the reflection cancelling effect shoud be at Maximum.
SO: When you are walking through your local drugstore..stop by the sunglass kiosk and pick up a pair of "Polarized' sunglasses and try what I have described above.
ROTATE the sunglass 90 degrees ..while looking at a reflection..and see the change. :look: NB