Today I noticed a crack in Bob's dome, and it was right in front of his camera. So here is my fix in case any others have a similar issue. Tape an outline on the dome around your bot's eyes. Score the plastic at the tape with an X-acto knife. Cut out the majority of the material with tin snips then make regular cuts in the remaining plastic perpendicular to and up to the score marks. Then use pliers to snap out those smaller pieces of plastic along the tape/score line. You will need almost NO cleaning of the cut edge. Remove the tape then use a lighter to smooth the edge. The tape gives you a guide and keeps it from cracking. The plastic is soft and scores easily. Here is how Bob's turned out - good luck.
Upgrade to ARC Pro
Harnessing the power of ARC Pro, your robot can be more than just a simple automated machine.
Second, a moot point now but I'm curious, couldn't you have just turned the dome completely around so the crack wasn't in front of the camera? Then you wouldn't have needed to cut the hole in the plastic. Or wouldn't that have worked for a reason I don't see? *confused*
Again, great job on the dome and I very much like the "helmet" look of it!