Try some non polarized sunglasses. I was sitting co pilot flying in a jet a while back, and mentioned the windshield glare, polarized glasses was the issue. Oakley Flackjacket XLJ.
Another help I recommend is Plexus cleaner. Spray it on a cool windshield, and let it sit a few minutes. Then microfiber it off.
Weird the things you see with polarized glasses thru car windows - checker boards, dots, all kinds of stuff. But, they do help you to see fish in the water, for sure!
Free cheap test - put on your sunglasses and look at your computer screen with it turned on. Turn your head side to side. If the screen blacks out anywhere, they are polarized.
As stated, pros and cons to polarized lenses, just offering help for your issue...

 

Well shut my mouth...lol
Went out today , different glasses. I took 2 sets. The first had very little rainbow depending on the direction of the sun. The second set had none at all.
So why the difference between stock Harley, Memphis shades which I have used in the past and never seen this before????
I need to find a good cheap set of a sun/riding glasses.......

 

Polarized glasses can be funky. I have a watch with a digital LCD screen that looks perfectly normal with the naked eye, but with my polarized glasses on that watch screen looks almost like it has a cigarette burn or something in the middle of the screen, non polarized it looks just fine.
With regard to "Cheap Riding Glasses", be sure you get something with UVA/UVB protection as well as good impact resistance. Safety first!
Ride safe...

 

Bought these may or may not .....
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

 

I have the LRS windshield and when I wear my HD PPZ (partially polarized) sunglasses I see the rainbow effect a
So.

 

I use the ESS Crossbow. You can get polarized or non-polarized lens. I paid a little over $100 for the frame and 3 lenses. These glasses will protect your eyes. These are issued to our combat soldiers for eye protection. http://www.esseyepro.com/Crossbow_211_category.html

 

I have an 8 and 9 inch LRS. I only wear polarized sun glasses during the day. I'm not sure what rainbow effect you guys are talking about. I don't see anything abnormal. Also, don't look directly through the windshield when I ride. I prefer to look over the top. Isn't that the purpose of the recurve? To allow you to use a shorter shield and see over the top?

 

JWell the OP is talking about Road King shield not a bat wing if that helps.

 

Is your shield tinted or clear, that may be the difference if clear (like in your picture)

I too have a 9 inch Ultra Elite shield with medium tint, the rainbow is 110% due to the polarized glasses.
I also have an 8 in standard Ultra, same thing, rainbow with polaized.
I prefer to look over the shield as well, but close up.... looking through the shield with polarized glasses makes road tar look like disco lights...lol.

 

Mine is clear and 18 inches, so I look over it somewhat.If you have the rainbow you will know. Disco lights for sure...lol

But once again why just this shield ?????
Others brands don't do it...