Reducing Scratches on clear visor; or where to get a new one

[Fazerider]

Visors these days have a hard coating... certainly last a hell of a lot longer than when I started riding. The downside is that to polish a scratch out you've got to keep going until the surrounding (hard) surface is down to the level of the bottom of the scratch. It should be possible, but it'll take a long time and the result will be a visor that is no longer scratch-resistant.
Long story short... it's time to buy a new one.