Since I bought new clear lenses for my car, I decided to experiment with the old ones to test out
sanding down the fluting on the inside of the headlight would turn out since there is so little information on it (this is not removing the yellow, that took me 5mins with 1500grit wet sanding and some polish!).
All sanding was done by hand, without a sanding block (just raw sand paper).
I started off with 60grit sand paper, which took roughly 6-7 hours to do the patch in the pictures. From there I moved to 400grit for about thirty mins, followed by 600, and finally 1500 grit. Once it was sanded, I applied Maguires PlastX clear plastic cleaner and polish to remove as many of the sanding marks as possible. Here are the results:
Clarity (sanded down):
Compared to stock:
As you can see, it does actually become relatively clear. I wouldn't say it is by any means a beautiful finish, but it can be done. Overall, I'd say the only way this is worth it is if you have 10-20 hours of time to dedicate to good sanding, or else a much more efficient way to sand (obviously I'm not extremely experienced with sanding and finishing.)
I just thought I would put this Information out there, when I did a search in google and many forums, I found next to nothing on this subject.