DOT does not approve aftermarket headlamps, nor does the SAE.
Aftermarket lamps need to meet no requirements to be sold, and most beam patterns compared to OEM, lights are jokes, which nobody will ever acknowledge.
POlishing basically removes the original failed UV protectant and clouding will return even faster afterwards.
One can use wetsanding techniques in steps upto to 3500 grit if they want, starting with 600 or perhaps lower grit, and then apply a UV clearcoat and extend the life of their efforts.
https://www.amazon.com/U-Pol-Products-0796-Clear-CLEAR/dp/B009LHER0M
http://www.candlepowerforums.com/vb/showthread.php?426653-Cloudy-Aftermarket-vs-New-OEM-Headlamps
I despise Glare from aftermarket lights, or HID or LED bulbs in halogen housings. I will return the favor with my high beam assists, and we will both see spots before our eyes. Childish I know. So be it.