I had a similar discussion a few days back.
And while we came to the conclusion that having a glass canopy is fair game (design perspective and all). But we did agree that adding a protective armored shell and cameras for outside view would be really cool when installing heavier, especially mil. grade armor.
I'd really love to see some outside changes to the ships when installing higher grade armor, like additional plates being fixed over weak/important points on your ship.
In the case of the canopy this could mean that installing mil. spec. armor would provide you with an armored shell for your canopy and cams on the outside that would project what you would see through the canopy onto the inside of the shell. In case of (battle) damage and the cams being knocked out, the armored shell would jettison and reveal the canopy again.
All topics on how to balance this aside, I think this would really add to the feel of flying a ship specced for combat.