Sunglasses

NoBozo · 08-20-2012, 07:35 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.

NB

Lakesrider · 08-20-2012, 08:31 PM

I can also tell when looking at a cars window or windshield with a polarizing film. It will seem black or splotchy looking.

ApS · 08-20-2012, 08:43 PM

Hold a polarized lens in front of your camera's lens when taking pictures of underwater objects:

ITD · 08-20-2012, 09:23 PM

I check them by grabbing two pairs of the same polarized glasses. Hold one lens in front of the other and look thru, you should be about to see thru the lenses, then turn one pair 90 degrees to the other, the amount of light transmitted thru should be significantly less.

no-engine · 08-21-2012, 09:52 PM

I have had my prescription polarized sunglasses, for several changes.
Driving and on the water are great uses. I can add that by definition, the polarizing minimizes reflections from non-metalic surfaces, such as glass, water, the boats fiberglass decking and hull, highway pavement (excellent when driving), the dash of car, snow when skiing, and all sorts of great uses!

More money than non-polarized prescription sunglasses, but I think well worth it. Buy a neutral color.

08-20-2012, 07:35 PM	#1
NoBozo Senior Member Join Date: Jun 2008 Location: Portsmouth. RI Posts: 2,231 Thanks: 400 Thanked 460 Times in 308 Posts	Sunglasses 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. NB

08-20-2012, 08:43 PM	#3
ApS Senior Member Join Date: Jan 2005 Location: Florida (Sebring & Keys), Wolfeboro Posts: 5,941 Thanks: 2,213 Thanked 778 Times in 554 Posts	There's more and better... Hold a polarized lens in front of your camera's lens when taking pictures of underwater objects: Attached Images

The Following 3 Users Say Thank You to NoBozo For This Useful Post:
diprna (08-20-2012), Jonas Pilot (08-20-2012), NHBUOY (08-20-2012)

08-20-2012, 08:31 PM	#2
Lakesrider Senior Member Join Date: Jun 2007 Posts: 2,129 Thanks: 380 Thanked 1,016 Times in 345 Posts	I can also tell when looking at a cars window or windshield with a polarizing film. It will seem black or splotchy looking.

08-20-2012, 09:23 PM	#4
ITD Senior Member Join Date: Apr 2004 Location: Moultonboro, NH Posts: 2,931 Thanks: 478 Thanked 693 Times in 388 Posts	I check them by grabbing two pairs of the same polarized glasses. Hold one lens in front of the other and look thru, you should be about to see thru the lenses, then turn one pair 90 degrees to the other, the amount of light transmitted thru should be significantly less.

08-21-2012, 09:52 PM	#5
no-engine Senior Member Join Date: Jul 2008 Location: West side Winnipesaukee, Lakes Region Posts: 516 Thanks: 20 Thanked 52 Times in 40 Posts	I have had my prescription polarized sunglasses, for several changes. Driving and on the water are great uses. I can add that by definition, the polarizing minimizes reflections from non-metalic surfaces, such as glass, water, the boats fiberglass decking and hull, highway pavement (excellent when driving), the dash of car, snow when skiing, and all sorts of great uses! More money than non-polarized prescription sunglasses, but I think well worth it. Buy a neutral color.