Scratches on the laser glass

Well, I've had the G4 for a week and I've noticed that the focus laser glass gets easily scratched. It already has various scratches, they're really hard to see, yes, but they're there and I hate them. The laser works perfectly, but I want to know if this is normal, if I've done something bad or if this has happened to you too. Is hard to change this glass? Are there any stores selling it?
Thanks in advance.