Clear resin filler to repair cracked indicator

[Pondrew]

Hi all,
I have a very small crack in the polycarbonate mirror-mounted indicator repeater on one of my other cars. It is small and you can't feel it with a fingernail (looks like it was caused by a stone) but annoying and I don't really want to replace the expensive mirror complete.
Does anyone know of some kind of "resin injection" for this; I was thinking like the windscreen people do with small chips?
I googled it and some stuff came up but nothing specific for this.
Pics of the offending item:

IMG_8313.JPG (62.92 KiB) Viewed 692 times

IMG_8307.JPG (68.66 KiB) Viewed 692 times

[Crawford08]

I've never seen anything that would be used on clear plastic. The biggest problem you'll have is material compatibility because one manufacturer might use an acrylic based lens while another uses a polycarbonate material. With windshields they're all glass so the resins are a little more universal. Also any solvent that would melt the crack closed usually makes plastic swell and makes the cracks worse

[Mister T]

I'd try a windscreen chip repair kit.

[Pondrew]

Thanks for the replies.
I have left it as didn't want to make it worse.
I have taken a hit of £100 off the price of the car which is a lot cheaper than a new mirror.