Out of necessity you need repairs when replacement isn't possible of immediate. I was practicing for this past weekends ASA 3D Qualifier when decided my scope lens needed cleaning. It has tiny spots here and there. Evidently, these spots were tiny sap droppings from the evergreen tree that I shoot under, but then I didn't know these spots were sap. Garage right at hand and this Windex no streak window cleaner available I began to clean. Soaked the lens and started drying with a clean soft cloth. Not paying attention, cloth rather big I didn't notice the hazy was scuffs and scratches. Lord! Held the lens up and could barely see the 25 yard target face. Try to wipe the hazy away and wouldn't go away. Ruined was all I could think. Half a dozen lenses laying around and not one of them would fit this Extreme Eagle Scope Housing. So I tried to other scope housing and lenses and I didn't care for them. Look in the Lancaster catalog and couldn't find my odd ball size lens, 1.737" in diameter. 1.625" and 1.750", sure, but no 1.737".
Desperate, I jump on the internet and Google polish plastic lenses. Bang. First try and there was "Removing scratches from acrylic and plastic lenses." Brass Polish. Yes, brass polish for cleaning brass, copper, silver and so on. Brasso and a couple others were given. Right in "My Leave It Alone" basket was Simichrome Polish. Hey, I hand polished a entire 1972 Harley Sportster with Simichrome back in my terrorizing the street days. You have to look up Removing scratches to get the correct instructions, but cotton balls, cotton swabs, soft cloths will work.
This removing of scratches is not for the weak of heart or those in a rush. It plain just takes time. Best results for me was a soft cloth and polishing until the Simichrome was dry and then use a soft cloth to light buff. Two sides to every story, two sides to every lens and you can't tell if you got the scratches out until you polish both side. Mercy....
I got it done. Whew! But I only got the main center of the lens clear on the first good polishing. I don't know, about a hour and then later, after the 3D, another hour before I most all the lens clear. The tiny bit on the edge of the lens didn't matter as the lens set on a ledge and the ledge covers up the hazy yet edges of the lens.
Tried to take some pictures. If it wasn't raining, it was drizzling and then overcast. So I got flash back on the lens. Even so you can see there are no scratches now.
On both pictures, look at 9:00 on the lens, about 1/16" in and down a 1/4" is a gray area. That's how the lens looked before polishing.