I have to ask how did you manage to scratch your lens? LOL
But I think you should be fine with using a plastic cleaner and buffing it out, something like Plastx. I had a few of these scratches on my altimas speedometer gauge lens from my keys (don't ask lol), and used some of this on it:
Meguiar's PlastX Clear Plastic Cleaner and Polish - 10 oz | Detailed Image just applied some and took a mf towel and wiped it clean then used a hand buffer to smooth it out.