That is true. The "polarization" process stretches the lens polymer into parallel lines, hence the effect of reducing glare from horizontal reflections (The light is actually polarized, and not the lens). The "polarized" lens is merely a filter that allows the random light to pass but blocks the reflection off of the horizontal surface.

When you twist the lenses you can see where the plastic is stressed by changes in the transmission pattern. The polarization effect in those areas is significantly reduced.

I think they laminate a polizing film to the glass.

And if only one lens is polarized you won't see anything either

This is LM90's girlfriend.

He thought I might like to respond to this and give my advice, from my experience. I have been working in optics for 7 years, and am ABO certified. From my experience the cheap polarized glasses are NOT the same quality as a pair you would get from your eyedoctor. I am not sure I would even reccomend a pair from cabela's. The most important things you need to look for are: polarization, and a back side anti reflective coating.
The polarazation will help with the glare off of the waters surface allowing you to look thru the water column. The backside anti reflective coating will eliminate the glare from behind, the side, and above. Which means you won't see the trees, etc. reflecting off of your glasses and distracting you while you are fishing. This will reduce eyestrain.
The brand name of the glasses really doesn't make any difference. With a lot of those you are only paying more for the brand name, not what the glasses are going to do for you. You are better off going to your eye doctor or an optical retail shop. Then you can get a custom made pair of glasses, and you can usually get them for under $200 if you watch for sales. You never want to pay full retail price for a pair of glasses, someone somewhere always has a sale going on. This way you can get the frame that fits you best, and the lenses and coatings that you want. Not just off the shelf one size fits all.
So my reccomendation is to see your eye doctor and pick out a frame you like and then talk to them about getting polycarbonate polarized lenses with a backside anti reflective coating. It may cost you a little bit more, but it's an investment that is well worth it. You can get these at any optical place, even places like Sam's Club (if they have an optical department), Wal-Mart, Vision World, Shopko, EyeMart Express, Pearle Vision the list goes on. But look for a good sale (50% off is the best time), and a frame that fits you well and a style you like.
One other things to ask them about is a polarized lens that blocks HEV (High Energy Visible) rays as well as UV rays. This is a fantastic option and not all optical places have the lenses yet. If you are going to spend the money for a quality pair of sunglasses this would be the best option.

LM90's Girlfriend, ABOC

P.S. Sorry for being so long winded, just wanted to help and eye care is my second love (and it's second only to my family).

Reading this i was a little suprised to see no one talked about Oakleys. I have a pair of polarized oakleys and i love them, there is no glare in water, i have had people who have regualar spendy oakleys not polarized look through mine and they almost craped there pants to see how different everything looked and how clear it was. My first pair not polarized lasted me almost 8 years, so im a firm beliver in the brand, and am more then willing to spend the higher price. Im a person that tries to always try the cheap something first but when it comes to your eyes i wouldnt take the chance, and when you see the quality you would be a beliver as well.

I have to wear prescription glasses now, but the Oakleys I had for 5 years were incredible for polarized filter. Much better than the best prescription glasses I have now.

you all do know that oakleys sells prescription sunglasses, right?

They do, but they ain't those one piece wrap around. or pay something like $1000.00 - glue the prescription onto anyframe

They dont cost $1000, the lenses will cost depending on your perscription like $100+ frame cost. I really have no idea what your talking about. My dad got a very nice pair of wire for like $400 probably

If you want a serious pair of prescription sun glasses for fishing then see Costa Del Mar, Smith, possibly Oakley. All three offer curved prescription lenses that work well in there frames. Unless your eye doctor is into hunting or fishing he/she may not be up on the performance eyeware available for our pursuits. For light reduction and safety while casting it's a good idea to wrap around frames. It's a bit more difficult to make prescription lenses that work in wrap around frames (so I am told by my eye doctor who likes to bone fish). The color coatings are geared for the type of water you frequent. Most Costa's are geared for open ocean, the Smith's for freshwater and/or streams - different colors for different environments. When I went shopping for my Smith's I saw some frames at various shops (frame/glass combo's that weren't prescription) to get an idea of fit. I then called up Smith and they sent me a couple of similar sized frames for me to try on. I found one that worked right so I faxed my prescription information to Smith, the frame choice, and the color I wanted (fly fishing midwestern streams so All Hour Brown) and I received a great pair within a couple of weeks. Total cost depends on what you want with the lenses (progressive, lined bifocal, single prescription, etc), and the frame. I believe mine totaled out at $250 a couple of years ago and they are still working just fine. The only reason for me to replace them would be if my prescription changes. They work great and have save my eyes from a couple of cast flies. Pearl or Sears isn't going to cut it.

if you have a prescription like I do, your choice of lense and frames might be somewhat limited. I have -5.5 and got a very nice pair of prescription polarized sunglasses. But my choices were limited by lense edge thickness. Talk to the place you get your glasses.

I also sometimes wear contact lenses. the new soft lenses can be worn at irregular intervals and allow use of regular sunglasses. They also don't fog up or get covered with snow.

Laser surgery is the last option. too bad I am too old for it.